three-dimensional ordered porous electrode materials for electrochemical energy storage - electrical energy storage systems

In the last ten years, three-dimensional (3D)
An orderly hole or pore structure (the so-
Called "reverse opals ")
For electrochemical energy storage device of application.
This review summarizes the latest progress in 3D ordered porous materials (3DOP)
The inherent and geometric structures of electrode materials give them unusual electrochemical properties.
The 3DOP electrode materials discussed here mainly include carbon materials, transition metal oxides (
Such as: ti02, sn02, coprovision, NiO, fe2o, v2o, Cu2O, mn, GeO2), etc.
Transition metal dihalides (
Such as MoS2 and WS2)
Basic substances (
Such as Si, Ge, Au)
A layer of compound (
For example, li4tio12, LiCoO2, lithium oxide, lithium phosphate)
And conductive polymer (
And use each of them).
Representative applications of these materials in lithium-ion batteries, water rechargeable lithium batteries, lithium-ion batteriesS battery, Li-
O2 batteries and super capacitors are introduced.
Special attention is paid to how orderly porous structures affect the electrical properties of electrode materials.
In addition, we discuss research opportunities and current challenges to facilitate further contributions to this emerging research frontier.
Continued exploration of green and sustainable energy storage devices is essential to address the limited supply of fossil fuels and environmental pollution worldwide.
Among all kinds of energy storage technologies, the most promising and commonly used are the electro-chemical energy storage devices.
At present, the research on batteries at home and abroad mainly focuses on super capacitors and rechargeable batteries.
The super capacitor has the high power density and long cycle life explained by the surface charge storage mechanism, while the rechargeable battery provides high energy density due to the Faradaic charge storage mechanism.
In the past 30 years, lithium-ion batteries have become the main power supply for various portable electronic devices.
However, the plug-in layer-
The type of electrode material for lithium ion batteries has reached the performance limit.
Therefore, people pay great attention
Capacity conversion reaction
Type cathode, such as sulfur (Li-S batteries)and oxygen (Li-O batteries).
Also, low
Cost and safe water-based rechargeable batteries are promising candidates for large batteries
Power storage system of scale.
For any kind of electro-chemical energy storage device, electrode material as its main component is the key factor to realize high energy and power density.
In the past 20 years, the development of high
The researchers designed and integrated a performance electrode material. dimensional (1D)(
Nano Wire, Nano belt, nano tube), two-dimensional (2D)(
Nano thin film, Nano thin film, Nano thin film), and three-dimensional (3D)
Structure of electrode material.
1D and 2D electrode materials with high stability and efficient charge despite
Transport pathways have been shown that they still suffer from severe aggregation, which hinders the rapid kinetics of easily diffusion of the electrolyte and the electrochemical reaction.
To this end, designing a three dimensional structure with interconnected porous channels is one of the most effective strategies to solve the above problems.
In addition, in the actual manufacture of electrodes for commercial batteries and super capacitors, electrode materials are squeezed to form a disordered 3D structure.
These 3D structures in commercial bulk electrodes will facilitate electrolyte transport and ion diffusion.
For 3D materials, extrusion processing during industrial production will result in a double
The 3D structure in the electrode is conducive to superior electrolyte transport and ion diffusion.
In a variety of 3D structures, 3D orderly porous (3DOP)
Structure is built high
Performance electrode materials in the electro-chemical energy storage system.
Typically, 3DOP materials are prepared through a colloidal crystal template strategy.
The first is a uniform, monodispersed sphere, such as polystyrene (PS)
Silicone or poly (
Mma)
Balls, assembled into a 3D ordered array through dense packaging.
Second, all kinds of front qualities can penetrate into the three-dimensional orderly scaffold.
Finally, the curing of the pioneer body and the removal of the colloidal ball were performed to obtain a periodic 3D frame structure.
There are two typical methods for obtaining 3DOP nano-composites.
In the first method, in the second step, the corresponding multi-component solution can be used as a precursor to introduce more desired active species directly into the 3DOP template.
In another method, the 3DOP material is used as the main structure to further grow the active electrode material through various growth mechanisms.
At present, it is generally believed that the spatial orientation/arrangement of the 3d op structure can not only shorten the diffusion path of ions in the thin wall of the electrode material, but also improve the solid structural integrity of the electrode material in the electrode process-time cycles.
Specifically, the 3DOP electrode material has a better rate capability than the Nano-crystal material (
Nanoparticles gather loosely together)
Because the double continuous ordered 3D frame can ensure a higher metal ion flux on the electrode and become a way to efficiently transmit electrons throughout the 3D bracket.
In addition, the free space within the porous 3D electrode can be used as a buffer for the volume change of the entire electrode, thus reducing the mechanical strain during repeated charge and discharge.
So far, many reviews have summarized 3D porous materials and their applications in the field of energy storage and conversion.
For example, several early reviews from the Rolison group focused on the design and manufacture of multi-functional 3D nano-structures for microcells, super capacitors, fuel cells and photovoltaic cells.
The synthesis and formation mechanism of porous mixed metal oxides and their application in lithium ion batteries were discussed in 2015.
In 2017, an overview of representative work on Holley 2D nano-materials
From the general method to its application prospect in various kinds of electro-chemical energy storage deviceswas provided.
However, with the rapid development of new materials and manufacturing technologies, there is still a lack of systematic review of the progress of 3DOP electrode materials used in the electro-chemical energy storage system.
In this review, we summarize the latest progress of the 3DOP electrode material and the unusual electro-chemical properties generated due to its inherent and geometric structure.
The representative 3DOP electrode materials and their applications in various electro-chemical energy storage devices are summarized (
Lithium ion battery, lithium ion battery, lithium ion batteryS battery, Li-
O batteries and super capacitors).
This paper focuses on the special 3DOP configuration and its corresponding influence on the enhanced electro-chemical properties.
Research opportunities and challenges were also discussed to facilitate further research and development in this promising area.
Titanium dioxide (TiO)
As an anode for lithium ion storage, it has been well studied because of its stable chemical properties, rich, cheap and environmental protection.
Three types of TiO, namely TiO (B)
Ruiti and TiO 2.
Among them, the main natural phase of TiO is the main phase, because it is the hottest mechanical stable phase under normal conditions.
The Li ion insertion layer and stripping in TiO involve a higher operating potential (1. 5u2009V vs. Li/Li)
Than graphite (0. 2u2009V vs. Li/Li).
Although this operating potential cannot completely prevent the formation of the solid electrolyte interface (SEI)
Film, eliminating the problem of the formation of lithium plating and shoot crystal.
Early research on the 3DOP TiO electrode for lithium-ion batteries dates back to 2007, when Professor Wu's team reported,
Compared with traditional TiO, synthetic TiO with 3DOP structure exhibits higher specific capacity and better cyclic behavior.
In fact, since the path length of Li ion diffusion is shortened, reducing the particle size of TiO to nano size can allow higher reversible capacity and faster charge and discharge rate.
Specifically, the dense accumulation of nanoparticles formed due to Aggregation reduces contact with the overall surface area of the electrolyte (Fig. ).
Therefore, it may not be possible to fully obtain a deeper active TiO nanoparticles for lithium.
For the 3DOP TiO electrode, the ordered pores of the electrode ensure a uniform distribution of contact between the electrode and the electrolyte, as shown in Fig.
Thus improving the mass transfer of electrolyte ions to the surface of the electrode and promoting complete lithium.
In addition, the thin hole wall in the 3DOP material makes the Li ion diffusion path short.
Therefore, 3DOP TiO electrodes have higher specific capacity and better rate capability than nanoparticles.
It is interesting to note that the initial discharge capacity of another 3DOP TiO electrode is up to 608 mahmahg, much higher than the theoretical capacity of TiO (
Mahmahg of LiTiO or 336 mahg of LiTiO).
Such a high capacity is mainly due to some defects that are formed as an additional cost
Location of compensation.
In addition, in the absence of any adhesive or conductive additive, the 3DOP TiO electrode achieves an impressive cycle stability of up to 5000 cycles.
During repeated insertion and removal of Li ions, nano-tile expansion in these 3DOP TiO electrodes, but still well maintained 3DOP even after 1000 and 5000 cyclesFig. )
It proves the extremely high level of structural integrity.
Therefore, another advantage of the 3DOP electrode is that its periodic OP structure allows the interconnected walls to expand into empty holes and prevent the walls from being fanized.
Through the collaborative double template of colloidal crystals and surface active substances, 3DOP TiO/C nanoparticles were prepared with phenol-formaldehyde sol as amorphous carbon source.
Detailed synthesis conditions, including the selection of chelating agent and temperature, were studied and optimized.
Pyrolysis using 3, 4-at 800 °c
The 3DOP TiO/C composite obtained uses pentadiene as the position agent, showing the highest specific capacity.
The TiO content in the thermal cracking TiO/C composite is about 70%.
With the decrease of TiO content and the increase of amorphous carbon content, 55% mahmahg was realized in another 3DOP TiO/C nano-composite material with 549 wt % TiO
The ultra-high specific capacity is derived from the contribution of the Li ion insertion layer to the non-graphical carbon.
Although the capacity of the 3DOP TiO electrode material is high and even exceeds the theoretical value, the main contribution to the capacity is within the potential range of 1. 5–3. 0u2009V (vs. Li/Li).
Such a high potential makes TiO-
Base anode material, only properly coupled with cathode material with high potential.
Due to its high theoretical capacity, the transition cobalt oxide is widely regarded as an attractive anode material for lithium ion batteries (
Chief operating officer of 890 mAh YPG and COO of 716 mAh YPG).
At present, the practical application of cobalt oxide in lithium ion batteries is seriously hindered by the poor long-term capacity maintenance.
Due to the relatively large volume change, the time cycle.
To alleviate this problem, CoO nanoparticles were captured using 3DOP carbon reverse Opal.
Even after 1000 cycles, the 3DOP CoO/C electrode shows a capacity of up to 674 mahmahg g, accounting for 94% of the theoretical capacity.
The 3DOP carbon structure is not only a continuous conductive network running through each other, but also a dimensional constraint for active nanoparticles.
In addition to 3DOP carbon, the 3DOP Ni scaffold is also uniformly used for the deposition of CoO nano-flakes.
The thickness of the CoO nano sheet can be easily controlled by adjusting the hot water growth conditions.
The initial discharge and charging capacity of the 3DOP CoO/Ni/Au electrode are 1478 and 1224 mahmahg respectively, which is much higher than the theoretical capacity of CoO.
The additional capacity is due to the contribution of the alloy reaction of Li ions with Au.
The reversible redox reaction between Au and Li ions presents several sharp redox peaks below 0. 5u2009V (vs. Li/Li).
The redox peak of the naked 3DOP Ni electrode was not detected, indicating the stability of the 3D Ni as a support.
Among the various transition metal oxides, iron oxides are another anode that has been extensively studied because they offer a variety of benefits, including a high theoretical capacity (
FeO of 926 mAh YPG and FeO of 1007 mAh YPG)
High vibration density (5. 1–5. 3u2009gu2009cm)
Rich resources and friendly environment.
A recent study shows that 3DOP α-
FeO with a Aperture of 250 nm has the initial discharge and charging capacity of 1883 and 1139 mahmahg, respectively, compared with α-
FeO with 1D nano-rod structure or 2D nano-sheet structure.
In another job,
At room temperature, FeO nanoparticles were deposited on 3DOP Ni by pulse voltage deposition method.
In order to avoid the formation of a thick FeO layer on the top of the electrode, the process of pulse voltage plating must include a repeat sequence of "on" and "off" voltages.
It is worth noting that as the FeO load increases, the pore size in 3DOP Ni decreases, which may limit the accessibility of electrolyte to all active materials.
Optimized loading of gamma-
The FeO on the 3D Ni collector is 0. 4u2009mgu2009cm.
In the cycle Volt (CV)
Curve, there is a large reduction peak at about 1 place. 5u2009V (vs. Li/Li)
Does not exist in the first cycle, but appears at the beginning of the second cycle (Fig. ).
This phenomenon may be caused by the "electrolytic grinding effect.
"Smaller FeO particles are produced at the end of the first cycle.
Li ions can then be embedded in small FeO particles produced before they are completely converted into Fe and LiO, because the diffusion length provided by the small area is short and the surface area is high.
Therefore, this layer insertion process results in a large reduction peak of about 1. 5u2009V (vs. Li/Li).
Voltage lag of 3DOP γ-at room temperature
The FeO/Ni electrode is only 0.
62 u2009 v, calculated according to the separation between the oxidation and reduction peaks of the conversion reaction (Fig. )
Much smaller than the other reported FeO anode.
When the temperature rises to 45 °c, the voltage lag decreases and the value is only 0. 42u2009V (Fig. )
, Which indicates the voltage lag in 3DOP γ-
The FeO/Ni electrode may be generated during thermal activation.
Increase the inactive 3DOP current collector and low load
The active material on the 3DOP current collector causes low weight and volume capacity.
In this respect, a scaffold-
A free 3DOP FeO/C composite without any current collector or adhesive additive was recently shown.
For commercial potential applications, a FeO/C anode with a thickness of 100 m was realized, presenting a specific capacity of 710 mahmahg g based on the total mass of the entire electrode.
The change in the overall size of the electrode is hardly obvious, as the volume expansion shrinkage is buffered by the 3D nano-composite matrix.
In fact, the construction of the 3DOP structure and the formation of nano-composites do not completely solve the large inherent volume change and powder of the FeO anode.
In order to avoid the inherent powder of the FeO anode, the internal established magnetic field is obtained from the additional magnetic composition (CoPt)
Was introduced into the 3DOP FeO/TiO electrode.
Due to the magnetism of CoPt, after being magnetized by the external magnetic field, the constant magnetic field inside the anode can make the active substance tightly bind to the frame of the electrode even after crushing occurs. Tin dioxide (SnO)is also a well-
The anode used in lithium ion batteries is studied, and its charge storage mechanism is based on irreversible reaction (SnO/Sn+LiO)
Combined with reversible alloy reaction (Sn/LiSn).
As early as 2004, the electrochemical study of SnO anode with anti-Opal structure was reported, in which 3DOP geometry led to a decrease in polarization in the CV curve alloy region.
After the formation of LiSn from Sn, the theoretical volumetric expansion should reach 137%.
However, after riding the bike four times at 0.
At 1 ℃, the wall thickness of 3DOP SnO film was significantly swollen by 650%.
This is due to the continuous structural degradation of the Poles during the cycle resulting in the separation of additional LiSn particles, resulting in continuous expansion of the entire solid structure.
In addition, the expansion of the reunited LiSn alloy area gradually cracked, resulting in an increase in the proportion of electronic isolation and expansion particles.
When circulating at a high speed of 10 °c, no morphological changes were observed in this 3DOP SnO membrane electrode.
The other 3DOP SnO electrode has a higher reversible specific capacity (653u2009mAhu2009g)
Than SnO nanoparticles (327u2009mAhu2009g).
The continuous void space of the 3DOP structure can easily fill the electrolyte solution, thus improving the ion and electronic conductivity of the entire electrode.
Therefore, it may be concluded that the 3d op structure of the anode combined with irreversible reaction and reversible alloy reaction is more conducive to increasing the rate capability than to cyclic stability.
In addition to the SnO, a 3d op Sn scaffold containing a Sn hollow ball body coated with carbon has recently been shown.
The 3DOP Sn/C anode with an electrode thickness of 100 μm can maintain a capacity of> 100 mahcm after 650 cycles.
The 3DOP structure allows volume expansion and extraction of the active material without changing the overall electrode size during circulation.
Therefore, after various lithium state, no obvious volumetric expansion occurred in 3d op Sn/C composite (
The dotted yellow line in the figure. )
When in contact with Li/LiO flakes from in situ transmission electron microscopy (TEM)study. For the real-
The aging of 3d op Sn/C nano-composite material, a nano-battery device is designed, the device is composed of Sn/C nano-composite material as working electrode and Li metal sheet covered by natural thin LiO solid electrolyte layer as reverse electrode.
It is worth noting that the above-mentioned device using solid LiO as electrolyte on the surface of the Li anode is the most commonly used model for real nano-batteriestime TEM test.
However, such a solidstate set-
Using an organic liquid electrolyte, up does not accurately represent the standard battery environment.
In this regard, the in situ liquid TEM experiment is ideal by sealing the liquid electrolyte with two film windows.
However, the film window may greatly reduce the spatial resolution of the microscope.
Therefore, there is still a long way to go to realize in-situ TEM electrolysis of 3DOP electrode materials.
The comparative study of Si anode shows that the specific capacity is the highest among all anode materials, but the biggest disadvantage is the large volume expansion (400%)
In the process of alloy/de-alloy with Li ions, their practical application is greatly limited.
To solve the problem of powder, several silicon anode
Coating 3DOP Ni electrode (Si/Ni)
It is made by electroplating.
Based on the electrical impedance spectrum measurement, the Li ion diffusion coefficient of the 3d op Si/Ni electrode is greater than Si-nanowire-
Electrode-based due to different configurations.
In addition, the electronic conductivity of the silicon anode is relatively low.
The Ni bracket inside the structure can increase the electronic conductivity of the entire electrode.
In the case of these 3DOP Si/Ni anode, although it is claimed that the 3DOP Ni anti-Opal structure is effectively adapted to the volume change of Si, the decrease in capacity is still obvious.
Finite element (FE)
Analysis of coupling with experimental results to study Li ion diffusion-
Induced volume change of Si-and corresponding mechanical damage
Coating Ni anti-Opal structure.
After comparing the numerical results of the strain with the prior results in operx-
Ray diffraction (XRD)-
Based on the strain experimental data, FE method verifies the feasibility of predicting the mechanical behavior of 3D Si/Ni anode.
Specifically, the FE modeling is based on a Aperture of 500 nm and coated with 30-nm-
Thick Si active layer (Fig. ).
The model is then simplified to 1 sub-shell of 8 parts as a representative volume element of Si-
Coated Nickel anti-Opal electrode.
Finally, the Si and Ni structures are divided into 9063 and 696 four-element elements for calculation (de)lithiation (Fig. ).
Li concentration in (de)
The lithium process, Li ions diffuse to/diffuse to Si depending on the Li concentration gradient.
By simulation, the remaining Li concentration was 1.
After the first lithium-de-lithium cycle, Si 22 Molli per mole, which resulted in a 95% volumetric expansion compared to the original electrode.
This high volume change then results in strain between Si and Ni.
Specifically, in the process of lithium, the Si active layer extends to the pores and supports, the expansion of Si to the supports is constrained by the Ni supports, and the Ni supports place the Ni supports in a compressed state.
By predicting the plastic deformation of the Ni support during the lithium process, as shown in Fig.
, Showing the stress gradient between the node and struts, because the stress developed in struts is higher than the stress gradient in the node (de)
Lithium, resulting in mechanical degradation of the electrode after multiple Lithium Cycles.
Other chemically active anode materials such as graphene, TiNbO, MoS, Ge and GeO have also been designed as 3DOP electrodes for lithium ion storage. Few-
Due to the strong van der Waals interaction, single-layer graphene flakes tend to accumulate or reaccumulate, resulting in large interface resistance and hindering high
Rate electronic conductivity.
The synergistic effect of the anode structure and doping of 3d op graphene was proved for the long-term ultra-fast lithium ion storageterm cycling.
3 DOP graphene of nitrogen (N)and sulfur (S)
Co-doping of graphene oxide and sulfuric acid polystyrene assembled by cracking (S-PS)
A 3D continuous structure is formed with the help of a polyethylene-based surface active substance (PVP).
N atoms from PVP and S atoms from S-
PS was successfully doped into graphene sheets in situ.
The 3DOP N/S co-doped graphene electrode has a high specific capacity of 860 mahmahg g at 0. 5u2009Au2009g.
Even at the ultra-high current density of 80 aa g, the reversible capacity can still reach a high value of 20 mahma g, corresponding to the charging time of 10 s.
The N and S doping effects lead to external defects in the graphene base surface.
Li ions may spread to the sandwich space of graphene sheets through these external defects.
The special 3DOP structure is combined with the impurity doping effect, making the-
Super capacitor graphene electrode-
Like fast charging while keeping the battery
Like high capacity.
Of course, the ultra-fast charging power obtained from the laboratoryscale half-
Cell testing is not directly equivalent to high
Rate Capability of actual industrial batteries.
As far as super capacitors are concerned
As with the ultra-fast rate capability, electrode materials with a plug-in capacitor should be the best choice for charging and discharging processes in minutes or even seconds.
3DOP TiNbO consisting of interconnected sheets
Crystal nanoparticles have the properties of Li ion pseudo-capacitor storage.
Proportion of surface-capacitance-
At 0, the controlled capacity was determined to be 51% and 79%. 05–1u2009mVu2009s (Fig. ), respectively. The diffusion-
The controlled charge is mainly generated near the peak voltage.
The unique 3DOP structure consisting of interconnected nanoparticles provides enhanced capacitive charge storage, resulting in a good rate capability.
As a typical layered transition
Metal sulfur, MoS has a structure similar to graphite in which the hexagonal layer of Mo is sandwiched between two S layers.
The S-Mo-S layer is combined by Van der Huali, and the larger layer spacing (0. 62u2009nm)
It provides an ideal channel for the diffusion of Li ions and the transportation of electrons.
3DOP MoS/C was assembled on the carbon cloth (CC)
, Where the surface of each carbon fiber is a small number of ordered holes connected by 3D-
Multi-layer MoS/C nano sheet.
The content of MoS flakes in MoS/C/CC hybrids is about 55%.
It provides a high discharge area capacity of 3. 802u2009mAhu2009cm (1130u2009mAhu2009g)at 0. 1u2009mAu2009cm.
The calculation of quantum density functional theory reveals that Li ions in (100)
The MoS aspect is stronger than the others.
This shows more exposure (100)
The surface should be more conducive to improving the specific capacity and rate capability of MoS anode.
Also, edge-
Very few-
Layer MoS flakes with a transverse size of 5-10 nm are evenly incorporated into the 3d op carbon Wall, avoiding the reassembly of MoS and exposing more activity (100)facets.
Ge can be reversible with Li ions to form LiGe alloys with a theoretical capacity of 1638 mahmahg.
In addition, the Ge anode presents a faster lithium ion diffusion coefficient at room temperature (
The diffusion coefficient is 4.
55 u2009 × u2009 10 u2009 length u2009 s General Electric and military.
61 u2009 × u2009 10 u2009 length u2009 s Si)
And closer to the conductor than the Si anode (
The band gap is 0.
66ev ev of Ge and 1. 11u2009eV for Si).
However, similar to the Si anode, the Ge electrode experienced a drastic volume change during the alloy-de-alloy process, resulting in a rapid attenuation of capacity.
3d p Ge electrode was prepared by ionic liquid (IL)
Plating directly on ITO and copper substrates, followed by PS template etching process.
The 3d p Ge electrode shows a much lower charge
Larger than the transfer resistance of the Ge electrode.
Initial discharge-and charge-
The specific capacity of 3DOP Ge is 1748 and 1024 Mach, respectively.
After 50 cycles, the material still retains a very high reversible capacity of 844 mahmahg g.
The surface of the entire 3DOP structure was rough but no obvious crack formation was observed.
Even with higher lithium ion storage capacity and satisfactory cycle stability, Ge's scarcity and high cost may still hinder its further mass production compared to other metal alloy anode
Scale applications.
The research on commercial cathode materials in lithium ion batteries is mainly focused on LiCoO and LiFePO.
LiCoO is the first commercial cathode material with an oxidation-reduction potential of about 4. 0u2009V (vs. Li/Li)
Moreover, the actual specific capacity of lithium is usually less than 0 in LiCoO. 5.
Excessive displacement can lead to phase transitions from single phase to six Phase, resulting in sudden shrinkage along the axis and disorder of the cation. The olivine-
Structured lifpo is considered the most promising alternative to LiCoO due to its large theoretical capacity (172u2009mAhu2009g)
Low cost and friendly environment.
Its main disadvantages are poor conductivity and rate capability.
To overcome the problem of low electronic conductivity, conductive reagents are usually applied on the lifpo electrode.
Early studies of the 3DOP LiCoO cathode show that the 3DOP structure can improve its specific discharge capacity at a higher current rate, but because of the small particles in the 3DOP wall in the cycle, the particles are disconnected.
The circulating stability of 3DOP LiCoO cathode synthesized at lower pre-burn temperature is poor.
The 3DOP LiCoO roasted at 700 °c presents a better crystal frame with a typical anti-Opal structure.
It shows a specific discharge capacity of 151 mahmahg g at a current density of 1 °c, higher than the commercial LiCoO.
In addition, after 50 cycles, the specific discharge capacity of 92% is retained.
Graded 3DOP LiFePO/carbon composite with macro-hole/intermediate-hole/micro-hole was synthesized by multi-component and two-component
Template method.
This material has a special capacity of 150 mAh u2009 g.
When the current density increases to 16 mahc, there is still a capacity of about 65 mahmahg g.
Three types of 3DOP LiFePO samples were produced using colloidal crystal balls with different diameters of 100, 140 and 270nm.
3DOP life po with 270-
The Nm colloidal crystal template shows a high surface area and an improved electrolyte channel, thus having the highest discharge capacity.
In addition, the smaller colloidal crystal template (100u2009nm)
Excessive residual carbon was produced in the obtained LiFePO sample.
Although adding carbon to the lifpo electrode can improve the conductivity and overall electrical properties, excessive carbon in the liFePO electrode will prevent the electrolyte from fully infiltrating into the pores in the center of the LiFePO particles.
LiMnO has attracted wide attention due to its high theoretical capacity of 285 mAh YMG and practical capacity up to 200 mAh YMG.
The LiMnO crystal has a layered hexagonal structure and an oblique structure, and the Li and Mn are arranged in a zigzag shape.
At present, the research on LiMnO mainly focuses on the oblique phase, because the synthesis of the oblique phase is very difficult.
In order to obtain 3DOP LiMnO, The MnO was electrodeposited into the 3DOP Ni frame and subsequently deposited in the molten salt.
The 3DOP LiMnO electrode thickness is 30 µnm 198 µmah µg presents a special capability.
Even at 185 FOMC emissions, it still retains a specific capacity of 75 mahmahg g, about 38% of its initial capacity (Fig. ).
The 3DOP LiMnO/Ni electrode provides fast ion and electronic transport in the electrolyte, electrode and current collector.
Recently, fast.
With the increasing popularity of micro-electronics technology, micro-power supply needs to be continuously developed.
In this context, a lithium-ion micro-battery based on a 3DOP cross-finger LiMnO micro-electrode is reported, which uses an electroplating method on a cross-finger Gold current collector (Fig. ).
The width of the finger electrode is 30mm and the spacing is 10mm (Fig. ).
The energy density of this lithium ion battery is 2.
Month of 5 µwh 2017cm 2017µm. 5u2009C.
Even at 1000c, it still retains 28% of its original energy. The high-
The biggest advantage of lithium ion micro-battery based on 3DOP electrode material is power transmission.
Another cathode is 3DOP LiMnO, 3DOP Ni-
Making Sn alloy as anode through 3D holographic exposure and traditional exposure, and then through the template-
Auxiliary plating.
The volume energy density of the obtained micro-cell is 4. 5 and 0.
6 mu whcm mu m at 1 and 1000 mu C, respectively.
For practical applications, traditional lights
Drive LEDs with 500-
Peak current of μ (600 FOMC discharge)
The micro battery with a thickness of 10 μm above.
After 200 cycles, the output current of this micro-battery is still 440 μA, and the capacity attenuation is only 12% (Fig. ).
The bulk energy and power of the MicroCell exhibit a strong correlation with the structural parameters of the cross-finger electrode, such as air holes, shapes, digit widths, and air holes.
Of course, for small electronic products, volume energy and power density are not important than area energy and power density.
However, due to the limited electrode thickness, the surface energy density of the above-mentioned lithium ion Microcell is still relatively low.
As a substitute for phosphate (i. e. , LiFePO), silicates (i. e. , LiFeSiO)
Attracted the next great interest.
Lithium ion batteries produced in recent years.
Low electrical negative of Si (2. 03)than of P (2. 39)
It will reduce the band of electrons and increase the transmission of electrons.
It is important that LiFeSiO can pass the potential two-
Electron transfer reaction
Plus, Earth-
Rich elements Fe and Si are cost-
Effective and scalable resources.
Recently, 3DOP LiFeSiO/C composite was prepared by "hard-soft" template method.
3d op life sio/C cathode with high reversible capacity and excellent length of 239 mahmahg g-
In 100% cycles, the capacity maintains a long-term cycle stability of nearly 400.
Li ion diffusion coefficient calculated in 3DOP life sio/CF (
Carbon nano fiber
Among them, LiFeSiO/CF is 7 respectively. 62u2009×u200910 and 4.
54 × 10 cms s, respectively.
The ordered atmospheric pores produce short Li ion diffusion paths and adapt to volume changes, while the carbon matrix acts as a conductive network to improve the electronic transmission of life. LiV(PO)
With high oxidation and reduction potential (3. 8u2009V vs. Li/Li)
The theoretical capacity is relatively high (197u2009mAhu2009g).
In addition, Dove (PO)
Conductor with sodium ion (NASICON)
The structure provides a very high ion diffusion coefficient (
From 10 to 10 cms s).
However, it has low electronic conductivity (2. 3u2009×u200910u2009Su2009cm)
It limits its practical application. Carbon-Apply 3DOP Liv (PO)
Successful by a simple synthesispot procedure. This 3DOP LiV(PO)
The/C cathode shows a significantly increased rate capability relative to the corresponding large bulk nano-composite material.
After 60 cycles, the high reversible capacity of 148 mahmahg was retained at 2 c, and the capacity loss was only 0. 08% per cycle.
Further improve the electronic conductivity of LiV (PO)
A series of Ce-
Doping 3DOP LiVCe (PO)/C materials (=u20090, 0. 01, 0. 03, 0. 05)
Obtained and evaluated as a cathode for lithium ion batteries.
The doping of Ce elements does not affect the formation of 3D ordered pore structure. The 3DOP LiVCe(PO)
The/C electrode has the best electrical behavior in four samples.
The radius of the Ce ion is much larger than that of the V ion.
Unit cell volume of LiV (PO)
/C increased after proper Ce doping.
This expansion in the lattice may increase the diffusion rate of Li ions entering LiV (PO)lattice.
Recently, the electrical properties of a 3DOP VO cathode for Li ion storage were reported.
The 3DOP VO electrode presents a series of discrete redox peaks.
The subsequent CV curve period of the 3DOP VO electrode is much smoother than the initial period because an irreversible ω-
The LiVO phase was confirmed by in situ Raman spectroscopy.
It is worth noting that the walls of the 3DOP VO structure become thicker after 100 cycles, due to the volume changes associated with lithium.
In addition, crushing appeared in some areas of 3DOP VO.
Therefore, the 3DOP VO electrode on the stainless steel current collector shows a significant decline after 100 cycles compared to the initial capacity of 151-51 mahmahg g. When using FTO-
The coated glass acts as a current collector and after 75 cycles it exhibits a better cycle capability with a specific capacity of 191 mahmahg g. Then graphene-
In order to further improve the stability of bicycle sports, the 3DOP VO of the package is displayed.
A conductive graphene sheet with a thickness of 4-10 layers is embedded in the two-layer thickness of VO.
The obtained 3DOP VO/graphene/VO electrode shows the capacity of about mahmahg g in 1000 cycles.
In addition, the 3DOP graphene embedded in the VO cathode can achieve good electronic conductivity for rapid electronic transmission.
This is for high-
Due to the poor electronic conductivity of VO electrodes, the performance is good.
Interestingly, the symmetric Microcell based on the VO film is limited to 3DOP anode alumina (AAO)microchannels.
By deposition using an atomic layer, a 7. 5-nm-
Thick Ru layer as current collector and 23-nm-
The thick VO film of the active material is evenly coated on the AAO nanotubes array.
The VO on one side is pre-printed into a positive pole, and the original VO film on the other side is used as a cathode.
In the 3DOP micro-channel template, VO electrodes tend to expand after lithium and form a uniform structure in the micro-channel in multiple cycles.
This may prevent thin
The membrane active material falls off the electrode during the cycle, thus achieving a long time
Life of a period of up to 1000 cycles.
In addition to improving the cyclic stability, the enhanced dynamics of the Li ion insertion reaction are shown in the interconnected 3DOP VO electrode, which is related to increasing the Faradaic reaction utilization on both surfaces
Leading and bulk diffusion-
Dominant reaction.
In addition, symmetrical VO microcells with low voltage can easily be extended to VO-SnO asymmetric microcells with high voltage.
Trifluoride iron (FeF)
Is another promising cathode material, due to its high theoretical capacity of 237 mAh u2009 g (1-e transfer)and 712u2009mAhu2009g (3-e transfer). Poly(3,4-
Ethylene dioxygen and)(PEDOT)
Coated on the 3DOP FeF electrode by in situ polymerization.
The 3DOP FeF electrode without a conductive PEDOT coating shows a specific capacity of 148 mahmahg g, well below 3DOP FeF-PEDOT (210u2009mAhu2009g).
The uniform coating of the conductive polymer greatly improves the conductivity of the 3DOP FeF electrode.
However, the capacity shown by commercial hole-free FeF electrodes coated by conductive PEDOT is only 5. 0. mahg g.
This result shows that conductivity is not the only key factor, and the 3DOP structure also plays a key role in improving the electrical properties of the FeF cathode.
ARLBs is one of the most promising alternatives for large cars
Due to its advantages of safety, low cost, ultra-high speed charging capability and environmental friendliness, it can be applied on a large scale.
As the most commonly used cathode in ARLBs, spinel-
The LiMnO type has attracted more and more interest in basic and practical applications.
In a neutral aqueous solution, the 3DOP LiMnO electrode holds a capacity of 93% after 10,000 cycles (Fig. ).
In 2000 cycles, the capacity of the bulk LiMnO electrode decreases rapidly.
Ordered large pore structures can accommodate some strain/stress during charging and discharge, as evidenced by changes in the X-ray spectrum of 3DOP and bulk LiMnO electrodes before and after 10,000 cycles.
3DOP LiFePO interwoven with carbon coating and multi-walled carbon nanotubes (CNTs)
Also showed ultra-high speed in 0.
5 m LiSO water electrolyte.
Even at a charging rate of 120 FOMC (30u2009s), 300u2009C (12u2009s), and 600u2009C (6u2009s)
The specific discharge capacity is still maintained at 97, 84 and 62 mahmahg (Fig. ).
In the water electrolyte, the charge/discharge rate of 3DOP LiFePO is nearly five times higher than the charge/discharge rate in the non-water electrolyte.
From scratch, it is shown that a special solid/liquid interface is formed on the surface of the lifpo, reducing the Li-
The dedissolution process realizes the rapid transmission of Li ions on the solid/liquid interface.
In order to further improve the working voltage and energy density of ARLBs, a new generation of water rechargeable battery was constructed using coated Li metal as anode and 3DOP LiFePO as cathode, with an average discharge voltage of up to 3. 30u2009V.
The lithium metal used is first coated with a gel polymer electrolyte (GPE)
Ion conductivity with 10 ss cm order of magnitude.
Then there's Lee's movie.
Solid fast lithium ion conductor)
Further placed on the surface of the GPE.
The LISICON film allows only Li ions to pass through to obtain a charge balance.
As a buffer, GPE can withstand the volume change of Li metal and prevent the reaction between lithium metal and LISICON film.
More importantly, since the GPE has a higher viscosity than the organic liquid electrolyte, the formation of lithium shoots will be suppressed.
Due to the stability of the coated Li anode and 3DOP LiFePO in the water electrolyte for reversible oxidation-reduction reaction, the ARLB manufactured has an excellent cycle life and the Cullen efficiency is nearly 100%. Li-
S battery should be one of the most promising
Because they have a high specific capacity of 1672 mahmahg g and an energy density of 2600 whwhkg (
Including the quality of the Li anode)
Three to five times higher than the countryof-the-art Li-ion batteries. A Li-
S battery is a highly complex system with two typical electro-chemical reactions between lithium metal and elemental sulfur: many major problems caused by sulfur cathode and lithium metal anode hinder their practical application including poor conductivity of sulfur and LiS, large volume expansion of reversible transformation between sulfur and LiS, dissolution of lithium polysulfur compounds (
Such As LiS, LiS)
The instability of Li metal anode and the growth of shoot crystal.
In order to solve the above problems, people have been committed to the rational design of electrode structure.
In order to alleviate the problem of extremely low conductivity and large volume expansion during sulfur cathode cycling, an effective method is to use 3DOP carbon as a substrate (or host)
For insulating sulfur electrodes.
For example, 3DOP carbon coupled with the middle (3–6u2009nm)
It can be used as a framework for packaging intermediate products to inhibit the shuttle effect of lithium polysulfur compounds. N-
The doped 3DOP carbon is used as the main body of the Li-sulfur cathodeS batteries. The 3DOP N-
The doping C/S composite has achieved a long cycle life of up to 500 cycles with a capacity attenuation of as low as 0. 057% per cycle.
It is interesting to note that N-doping and 3DOP carbon co-operate to further capture soluble polysulfide compounds, thus achieving sulfur fixation.
In order to maximize the sulfur load in the region, a thick 3DOP N-is formed-
The doping C/S composite was realized.
Stacked interconnected NanoSphere clusters and high sulfur loads up to 5 cuccm.
This high-area sulfur load has commercial significance in replacing the current lithium-ion battery.
Still, long
Given the low affinity of carbon materials for sulfur-rich species, longevity remains unsatisfactory.
In order to improve the affinity of carbon hosts for sulfur-rich species, metal or metal oxides are introduced into the impurity-
The functional 3DOP carbon material can further reduce the multi-sulfur shuttle problem and facilitate the kinetics of the multi-sulfur oxidation and reduction reaction.
Specifically, novel 2in-one cobalt (Co)-embedded N-
The doped porous carbon sheet was prepared as a stable host for sulfur cathode and metal lithium anode.
On the one hand, due to the high electronic conductivity and excellent structural polarity of the polysulfide container, co nanoparticles can cooperate with N impurity atoms to promote the oxidation-reduction reaction kinetics and alleviate the solubility of polysulfide compounds, so, the sulfur cathode is endowed with excellent rate capability and long life of 400 cycles, with capacity attenuation