The 10 most promising new lithium battery materials

Lithium battery is in the development of a bottleneck stage. The energy density is close to its physical limits. We need new materials or technology to realize the breakthrough of lithium-ion batteries. The following battery materials were or will be the breakthrough to break down barriers of lithium battery.

1 silicon carbon composite anode materials

Digital terminal products after the big screen, functional diversification, put forward new requirements on the battery life. The current li-ion battery materials, capacity is low, can't meet the increasing demand for battery terminal.

Silicon carbide composites as anode materials in the future, its theoretical capacity is about more than 4200 mAh/g, class than graphite cathode of more than 10 times higher than that of 372 mAh/g, its industrialization, will greatly improve the capacity of the battery.

Now main problems of silicon carbon composite material are:

Charge and discharge process, the volume expansion of up to 300%, which can result in silicon particle pulverizing, material capacity loss. At the same time absorbing ability is poor.

Poor cycle life. Is through the nano silica powder, silicon carbon coated, doping methods to solve the above problems, and some companies have made some progress.

The related research and development enterprise:

At present the major material manufacturers in research and development of silicon carbon composite material, such as BTR, snow, star city, graphite, Huzhou, Shanghai Shanshan, Huawei, Samsung, etc. Domestic anode materials enterprise research and development situation of silicon material is: most of the materials are still on the stage of development, now only Shanghai Shanshan has entered the stage of pilot production.

2 lithium titanate

In recent years, the domestic research and development of lithium titanate enthusiasm is higher.

The advantages of lithium titanate are:

Long cycle life (up to more than 10000 times), belongs to the zero strain material (less than 1% volume change), does not generate the traditional meaning of the SEI film;

High safety. The lithium high potential, not generation dendritic, and at the time of charging and discharging, high thermal stability;

Can quick charge.

The main factors that restrict lithium titanate is used currently is price is too high, higher than that of traditional graphite, another lithium titanate g capacity is very low, about 170 mAh/g. Only by improving the production process, reduce production costs, long cycle life and fast charging lithium titanate advantages can play a role. Combined with the market and technology, lithium titanate is not suitable for the space requirements of the bus and storage areas.

The related research and development enterprise:

Zhuhai silver can long, Sichuan xing, Huzhou micro macro power co., LTD., Shenzhen bay, new energy materials co., LTD., Hunan Shanshan new material co., LTD. And Anhui province and Shenzhen around several smaller lithium titanate manufacturers.

3 the graphene

Graphene since won Nobel Prize in 2010, is a major global concern, especially in China. Bring an upsurge graphene research and development, it has many excellent properties, such as good pervious to light, conductive performance, high thermal conductivity, high mechanical strength.

Graphene in lithium ion batteries potential application are:

As anode materials. Graphene's capacity is higher, the reversible capacity of about 700 mAh/g, higher than that of graphite cathode capacity. In addition, graphene good heat conduction performance to ensure the stability in the battery system, and graphene layer spacing greater than graphite, make the lithium ion diffusion unobstructed in graphene layers and is helpful to improve the performance of battery power. Due to the not mature production technology, structure of the graphene unstable, there still exists certain problems result in graphene as anode materials, such as the first discharge efficiency is low, about 65%;Loop performance is poorer; The price is higher, significantly higher than the traditional graphite anode.

As negative additives, can improve the stability of lithium-ion batteries, longer cycle life and increase the conductivity.

Given the graphene mass production of the current technology is not mature, the price is high, the performance is not stable, graphene will take the lead in as is negative additives used in lithium ion batteries.

The related research and development enterprise:

Yoga wei, east lumena electricity, Qingdao HaoXin new energy, Xiamen chic, etc.

4 carbon nanotubes

Carbon nanotubes is a kind of graphitization structure of carbon material, itself has excellent electric conductivity, at the same time because of its small when take off the intercalated-li depth, short trip, as the cathode material in the big ratio when charging and discharging the polarization effect is small, can improve the battery charge and discharge properties.

Disadvantages:

Carbon nanotubes as lithium battery cathode material directly, will be irreversible capacity is high, the voltage hysteresis and discharge platform is not obvious. Using simple filter such as Ng single-walled carbon nanotubes was prepared, its directly as the cathode material, its first discharge capacity is 1700 mAh/g, the reversible capacity is 400 mAh/g only.

Another application of carbon nanotubes in the cathode is with other anode materials (graphite, lithium titanate, tin, silicon, etc.) composite, using its unique hollow structure, and the advantages of high conductivity and large specific surface area as a carrier to improve the performance of other anode materials.

The related research and development enterprise:

Day nai technology, nano port, etc

5 rich lithium manganese anode material

High capacity is one of the development direction of lithium battery, but the current of the anode material of lithium iron phosphate the energy density of 580 wh/kg, the energy density of nickel cobalt manganese acid lithium is 750 wh/kg, are low. Rich lithium manganese base of theoretical energy density can reach 900 wh/kg, become a research hotspot.

The advantage of rich lithium manganese base as the anode materials are:

The energy density is high, the main raw material is rich

Because the development time is shorter, the rich lithium manganese base a series of problems:

Discharge efficiency is very low, the material for the first time in the circulation process of oxygen, bring safe hidden trouble, cycle life is very poor, the performance of ratio is low.

At present the means to solve these problems are coated, acid treatment, doping, circulation, heat treatment, etc. Rich lithium manganese base despite the obvious advantages, capacity, huge potential, but limited to technical progress is slow, the mass market still need time.

The related research and development enterprise:

Chinese academy of sciences, Ningbo materials, etc.

6 power type nickel cobalt manganese acid lithium materials

For a long time, power battery route is quite controversial, therefore, lithium manganese acid lithium iron phosphate, ternary material route has been adopted. Domestic power battery route is given priority to with lithium iron phosphate, but as the tesla popular all over the world, the use of the ternary material route caused a boom.

Lithium iron phosphate, while high safety, its low energy density of weakness could not overcome, and new energy vehicles require longer range, so in the long term, g capacity higher material will replace the lithium iron phosphate as the next generation of the mainstream technology route.

Nickel cobalt manganese acid lithium ternary material is most likely to become a mainstream of domestic next generation power battery material. Domestic launch ternary route of electric vehicles, such as Beijing auto E150EV EQ, Jianghuai IEV4, chery, blue, etc., a unit of weight density lithium iron phosphate batteries. There is a big improvement.

The related research and development enterprise:

Hunan Shanshan, when science and technology, Xiamen tungsten, constant shares, etc.

7 coated membrane

The diaphragm is very important to the safety of the lithium battery, which requires the diaphragm has good electrochemical and thermal stability, and the repeated charging and discharging process to keep the electrolyte highly invasive.

Coated membrane is refers to the coating on the basement membrane PVDF adhesive or ceramic such as alumina.The role of the coated membrane is:

1, improve the diaphragm heat shrinkage, prevent diaphragm contraction caused extensive short circuit;

2, low heat conduction rate, coating material to prevent the battery point to expand to form the overall thermal runaway of some thermal runaway.

The related research and development enterprise:

Star source material, Shanghai jie, sinoma science and technology, YiTeng diaphragm, Tianjin east gao, tai pu han, etc.

8 of alumina ceramics

In coating membrane, the ceramic coating membrane mainly for power battery system, so its market growth space is glue diaphragm is bigger, the ceramic alumina market demand as the core materials ternary power battery rise of the surge.

Used to coat the diaphragm of the purity of aluminum oxide ceramic, particle size, morphology have high requirements, Japan, South Korea's products is relatively mature, but the price is expensive than that of domestic more than double. Domestic at present there are many companies in the development of alumina ceramic, want to reduce import dependency.

The related research and development enterprise:

The porcelain material

9 high voltage electrolyte

Improve the battery energy density is one of the trends of lithium-ion batteries, there are two main methods to improve the energy density is:

One is to improve the traditional anode material charge cut-off voltage, such as cobalt acid lithium charge voltage up to 4.35 V, 4.4 V. But on improving the method of charging by the voltage is limited, can lead to further enhance voltage cobalt acid lithium structure collapse, unstable nature;

Another is developing a new type of cathode material charge and discharge platform higher, such as rich lithium manganese base, such as nickel and cobalt acid lithium.

The anode materials boost voltage, needs to form a complete set of high voltage, electrolyte additive to the electrolyte of high voltage performance play a key role, it becomes a research focus in recent years.

The related research and development enterprise:

The new main bond, blessed materials

10 water-borne binder

At present the positive materials mainly using PVDF binder, dissolved in organic solvents. The cathode of the binder system with SBR, CMC, containing fluorine olefin polymers, etc., also can use organic solvents. In electrode production process, the need to drying volatile organic solvent, it pollute the environment, and harm to workers health. Evaporation of the solvent dry need special collection and processing, refrigeration and containing fluorine polymer and the solvent is expensive, increased the cost of production of lithium-ion batteries.

In addition, the SBR/CMC binder in machining process easy sticky roller, and difficult to preparation for positive plate, use scope is limited.

For environmental protection, reduce cost, increase the pole piece performance demand, the development of water-borne binder is imperative.

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