button battery 2025.10 major research progresses in ternary materials for lithium-ion batteries

1 High-nickel ternary materials Nickel, cobalt and manganese have the characteristics of high specific capacity, long cycle life, low toxicity and low price. In addition, there is a good synergistic effect between the three elements, so it is widely used. It is used as cathode material for lithium batteries. In redox energy storage, nickel is the main component. How to improve the content of the material?

1High nickel ternary material


Nickel, cobalt and manganese have the characteristics of high specific capacity, long cycle life, low toxicity and cheapness. In addition, there is a good synergistic effect between the three elements, so it is widely used. For lithium-ion battery cathode materials, nickel is an important component in redox energy storage. How to effectively increase the specific capacity of the material by increasing the nickel content in the material is one of the current hot topics of research.


Generally speaking, high-nickel ternary cathode materials refer to the mole fraction of nickel in the material being greater than 0.6. Such ternary materials have the characteristics of high specific capacity and low cost, but they also have low capacity retention and poor thermal stability. defect.


Material properties can be effectively improved by improving the preparation process. The micro-nano size and morphological structure of the particles determine to a large extent the performance of high-nickel ternary cathode materials. Therefore, the current important preparation method is to uniformly disperse different raw materials and obtain nanospherical particles with large specific surface areas through different growth mechanisms.
Low temperature lithium iron phosphate battery 3.2V 20A -20℃ charging, -40℃ 3C discharge capacity ≥70%

Charging temperature: -20~45℃ -Discharge temperature: -40~+55℃ -40℃ Support maximum discharge rate: 3C -40℃ 3C discharge capacity retention rate ≥70%
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Among the many preparation methods, the combination of co-precipitation method and high-temperature solid phase method is currently the mainstream method. First, the co-precipitation method is used to obtain a precursor with evenly mixed raw materials and uniform particle size, and then is calcined at high temperature to obtain a precursor with regular surface morphology and uniform particle size. Ternary materials with easy-to-control processes are an important method in current industrial production.


The spray drying method has a simpler process and faster preparation than the co-precipitation method. The morphology of the obtained material is no less than that of the co-precipitation method, and has the potential for further research. The shortcomings of high-nickel ternary cathode materials such as cation mixing and phase change during charge and discharge can be effectively improved through doping modification and coating modification. While suppressing the occurrence of side reactions and stabilizing the structure, improving conductivity, cycle performance, rate performance, storage performance, and high temperature and high pressure performance will remain a hot topic in research.


2 Lithium-rich ternary materials


The picture below is a schematic structural diagram of the lithium-rich ternary cathode material xLi2MnO3˙(1-x)LiMn1/3Ni1/3Co1/3O2 (0.1≤x≤0.5). Due to its special structure, it can extract more lithium and has a wide voltage The advantages of window and high specific volume have been favored by researchers in recent years.


This material has the characteristics of high voltage, and the first charge and discharge mechanism is different from subsequent charges: the first charge will cause structural changes, and this change is reflected in the charging curve with two different platforms separated by 4.4V. During the second charging process, the charging curve is different from the first curve. Because during the first charging process, Li2O was irreversibly detached from the layered structure Li2MnO3 and disappeared at the plateau of about 4.5V.
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Lithium-rich ternary cathode materials with different structures can be prepared using solid phase method, sol-gel method, hydrothermal method, spray pyrolysis method and co-precipitation method. Among them, the co-precipitation method is used more often, and each method Each method has its own advantages and disadvantages.


Lithium-rich ternary materials have shown good application prospects and are one of the key materials required for the next generation of high-capacity lithium-ion batteries, but they are subject to large-scale application.


The future research directions of this material are mainly in the following aspects:


(1) Insufficient understanding of the mechanism of lithium deintercalation and inability to explain the low Coulombic efficiency of materials and large differences in material properties;


(2) The research on doping elements is insufficient and relatively single;


(3) Because the cathode material is corroded by the electrolyte under high voltage, poor cycle stability results;


(4) There are few commercial applications, and the inspection of safety performance is not comprehensive enough.


3Single crystal ternary cathode material


Under high voltage, as the number of cycles of lithium battery ternary materials increases, the secondary particles or agglomerated single crystals may pulverize at the interface of the primary particles or separate the agglomerated single crystals in the later stage, causing the internal resistance to increase and the battery to be damaged. The capacity decays quickly and the cycle deteriorates.


Single-crystal high-voltage ternary materials can improve lithium ion transfer efficiency while reducing side reactions between the material and the electrolyte, thereby improving the material's cycle performance under high voltage. First, the ternary material precursor is prepared by co-precipitation method, and then single crystal LiNi0.5Co0.2Mn0.3O2 is obtained using high-temperature solid phase.


This material has a good layered structure. At 3 to 4.4V, the 0.1 discharge specific capacity of the button battery can reach 186.7mAh/g. The discharge specific capacity of the full battery is still 98% of the initial discharge capacity after 1300 cycles. , is a ternary cathode composite material with excellent electrochemical properties.


Xinzheng Lithium adopts a unique preparation process and designs and assembles an advanced lithium-ion battery cathode material production line by itself. It is the first large-scale production in the world of micron-sized single crystal particle modified spinel lithium manganate and nickel cobalt manganate. Lithium ternary cathode materials have reached an annual production capacity of 500 tons.


4 Graphene doping


Graphene has a two-dimensional structure with a single layer of atomic thickness, a stable structure, and a conductivity of up to 1×106S/m. Graphene has the following advantages when used in lithium-ion batteries: ① It has good electrical and thermal conductivity, which helps to improve the rate performance and safety of the battery; ② Compared with graphite, graphene has more space for lithium storage, which can improve the energy density of the battery; ③The particle size is on the micro-nano scale, and the diffusion path of lithium ions is short, which is beneficial to improving the power performance of the battery.


The JAN research team used the grinding method to first mix graphene and 811 ternary material, then stir it at 50°C for 8 hours, and then dry it to obtain the graphene/811 composite material. Due to the modified use of graphene, the capacity, cycle stability and rate performance of cathode materials have been significantly improved.


WANG adds graphene when preparing ternary precursors by precipitation method. The addition of lamellar structure graphene and its cavity structure reduce the agglomeration of primary particles, relieve external pressure and reduce the crushing of secondary particles. The three-dimensional conductivity of graphene The network improves the material's high rate capability and cycling performance.


5 high voltage electrolyte


Ternary materials have received more and more attention and research due to their high voltage window. However, due to the low electrochemical stability window of currently commercial carbonate-based electrolytes, high-voltage cathode materials have not yet been industrialized.


When the battery voltage reaches about 4.5 (vs. Li/Li+), the electrolyte begins to undergo violent oxidation and decomposition, causing the battery's lithium insertion and removal reaction to fail to proceed normally. Improving the stability of the electrode/electrolyte interface through the development and application of new high-voltage electrolyte systems or high-voltage film-forming additives is an effective way to develop high-voltage electrolytes.


In energy storage systems, ionic liquids, dinitrile organic compounds and sulfone organic solvents are currently mainly used as electrolytes for high-voltage ternary materials. Ionic liquids with low melting point, nonflammability, low vapor pressure, and high ionic conductivity exhibit excellent electrochemical stability and have been extensively studied.


Replacing all or part of the currently commonly used carbonate solvents with new solvents with high-pressure stability can indeed effectively improve the oxidation stability of the electrolyte. And most of the new organic solvents have the advantage of low flammability, which is expected to fundamentally improve the safety performance of lithium-ion batteries. However, most of the new solvents have poor reduction stability and high viscosity, resulting in the cycle stability of the battery anode material and the degradation of the battery. Reduced rate performance.


In high-voltage electrolytes, film-forming additives are also essential components. Common ones include tetraphenylphosphine, LiBOB, lithium difluorodioxaloborate, tetramethoxytitanium, succinic anhydride, and trimethoxyphosphorus. wait.


Adding a small amount (<5%) of film-forming additives to the carbonate-based electrolyte allows the oxidation/reduction decomposition reaction to occur prior to the solvent molecules and forms an effective protective film on the electrode surface, which can inhibit the carbonate-based solvent. subsequent decomposition. The film formed by additives with excellent performance can even inhibit the dissolution of metal ions in the positive electrode material and the deposition on the negative electrode, thereby significantly improving the stability of the electrode/electrolyte interface and the cycle performance of the battery.


Chinese Science: Chemistry, 2014, 44(8): 1289-1297


6 Surfactant-assisted synthesis


The performance of the ternary cathode material depends on the preparation method. It is prepared by co-precipitation method. Through the synergistic use of surfactants, ultrasonic vibration and mechanical stirring, the prepared flake precursor and lithium carbonate are annealed at high temperature to grow into a ternary layer. The structure is a new type of ternary cathode material synthesis process currently used.


It was found that using OA and PVP as surfactants can prepare regular hexagonal nanosheet cathode material precursors with excellent morphology, and the particle size distribution of the resulting nanosheets is relatively uniform, with a size of about 400nm. The surfactant has a great influence on the precursor. For good shape control purposes, the first discharge specific capacity of the assembled battery at the discharge rate of 1C is 157.093mAh˙g-1, and the capacity retention rate after 50 cycles at the discharge rates of 1C, 2C, 5C and 10C is greater than 92 %, reflecting good electrochemical performance.


7Microwave synthesis method


Among the important methods for preparing ternary cathode materials, the solid-phase method, co-precipitation method and sol-gel method all require high-temperature sintering for several hours, which consumes a lot of energy and has complicated preparation processes. Microwave heating is bulk heating caused by dielectric loss in materials in an electromagnetic field. The heating speed is fast and uniform. The synthesized materials often have better structures and properties. It is a very promising way to synthesize cathode materials.


Su Yuchang and others mixed the lithium source and the precursor in the measured ratio and placed it in a microwave oven, evacuated and introduced oxygen. They controlled the microwave power to achieve different rates of temperature rise. They heated to 750°C and then sintered for 20 minutes, and then naturally cooled to room temperature to obtain Cathode material.


The structure, micromorphology and electrochemical properties of the synthetic materials were characterized using XRD, SEM and charge and discharge methods. Experimental results show that the cathode material synthesized in a microwave with an output power of 1300W has a first discharge specific capacity of 185.2mAh/g under 0.2C charge and discharge conditions, a Coulombic efficiency of 84%, and maintains a capacity of 92.3% after 30 cycles. (2.8~4.3V), showing good electrochemical performance and application potential.


"Mining and Metallurgical Engineering", 2016, 36 (4): 104-108.


8 Infrared synthesis method


When infrared rays are irradiated on a heated object, when the wavelength of the emitted infrared rays is consistent with the absorption wavelength of the heated object, the heated object absorbs the infrared rays, and the molecules and atoms inside the object "resonate", causing strong vibration and rotation, and the vibration And rotation increases the temperature of the object to achieve the purpose of heating.


This heating principle can be used to prepare ternary cathode materials. HSIEH uses a new infrared heating roasting technology to prepare ternary materials. First, nickel cobalt manganese lithium acetate is mixed with water, and then a glucose solution of a certain concentration is added. The powder obtained by vacuum drying is roasted at 350°C for 1 hour in an infrared box, and then heated at 900 The carbon-coated 333-type ternary cathode material was prepared in one step by calcining for 3 hours under a nitrogen atmosphere at ℃. In the voltage range of 2.8 to 4.5V, the capacity retention rate was as high as 94% after 50 cycles of discharge at 1C, and the first cycle discharge specific capacity reached 170mAh/ g, 5C is 75mAh/g, and the high-rate performance needs to be improved.


Later, HSIEH also tried medium-frequency induction sintering technology, using a heating rate of 200°C/min and heating at 900°C for 3 hours to prepare 333 material with a particle size evenly distributed between 300 and 600nm. The material has excellent cycle performance, but its high-rate charge and discharge performance needs to be Complete.


9 Plasma synthesis methods


When using the traditional high-temperature calcination method to prepare ternary cathode materials, high synthesis temperatures, long calcination times, and large energy losses are required.


The study found that in a low-temperature plasma environment, the chemical activity of each reactant is high and the chemical reaction speed is fast, which can realize the rapid preparation of ternary cathode materials. Mix the nickel cobalt manganese oxide and lithium carbonate evenly, then put it into a plasma generator, and react at 600°C for 20 to 60 minutes under the condition of introducing oxygen to obtain the ternary cathode material Li(Ni1/3Co1/3Mn1 /3)O2.


The prepared cathode material has a high initial discharge specific capacity of 218.9mAh˙g-1, while the cycle stability, rate capability and high temperature performance are also due to the materials prepared by traditional methods.


RSCAdv.,2015,5,75145–75148


10 Preparation of ternary cathode materials from waste batteries


The cost of cathode materials for lithium-ion batteries accounts for 30%-40%. Therefore, by recycling waste battery cathode materials and using the preparation process to restore the energy storage performance of the cathode materials, the cost of lithium-ion batteries can be greatly reduced, and a complete The lithium-ion battery industry chain should include the recycling of lithium-ion batteries.


GEM invested 100 million yuan to build my country's largest waste battery and scrap battery material processing production line. It recycles more than 4,000 tons of cobalt resources annually, accounting for more than 30% of my country's strategic cobalt resource supply, forming the GEM battery material "from waste battery" "Come in, go into new batteries" recycling characteristic route.


The entire production line uses recycled nickel, cobalt, and manganese from used batteries to prepare a solution, add synthetic agents, and after a series of processes, it becomes a nickel-cobalt-manganese ternary power lithium-ion battery cathode material. Since it was put into production in October 2014, it has achieved an output value of nearly 200 million yuan, and it is expected to achieve an output value of 500 to 600 million yuan in the future.