What is the development trend of lithium battery electrolyte?

The electrolyte is the ion conduction between battery anode and cathode that effects as conductor, which is made from lithium salt, high purity of organic solvent and additive raw materials matching a certain proportion. It play a vital role in the battery energy density, power density, wide application temperature, cycle life and safety performance.

The lithium battery by the shell, the positive and negative, of the electrolyte and the diaphragm, including electrode materials is the focus of attention and research. But at the same time, one aspect of the electrolyte is also cannot be ignored, after all, occupy the battery cost 15% of the energy density of the electrolyte is also true that in a battery, power density, wide application temperature, cycle life and safety performance play a vital role.

Is the battery electrolyte is negative ion conduction effect between conductors, the electrolyte of lithium salt, high purity organic solvent and additive raw materials such as necessary to a certain proportion of the. Due to the lithium battery is finding wider and wider application fields, all kinds of lithium battery electrolyte to its requirements must also be different. Next, small make up is the development trend of the electrolyte analyses the key raw material for lithium-ion battery electrolyte.

1, high specific energy type electrolyte

The pursuit of high specific energy is currently lithium ion batteries one of the biggest research direction, especially mobile devices in people's life more and more proportion in the possession of, it life, become the performance of the battery is the most crucial.

The future development of high energy density batteries must be of high voltage anode, silicon anode. Cathode silicon has a large capacity and attention by people, but because of its swelling effect, its application in recent years, the research direction has been turned into silicon carbon negative, it has relatively high capacity and small volume change, different film forming additive in the silicon carbon negative effects on different aspects of the circulation.

2, high power type electrolyte

At present, the commercialization of lithium-ion battery is difficult to achieve high rate discharge, the main reason is that the battery pole ear fever is serious, internal resistance lead to overall battery temperature is too high, prone to thermal runaway. Therefore, we need the electrolyte in the case of high conductivity can inhibit the battery heating up too fast. And forPower battery, to realize the quick charge is an important direction of development of the electrolyte.

High power battery not only puts forward high solid diffusion on electrode materials, nano make ion migration path is short, the control sheet thickness and compaction requirement, also puts forward higher requirements on electrolyte: 1, high dissociation degree of electrolyte salt;2, solvent compound - lower viscosity;3, interface control - membrane impedance is lower.

3, wide temperature electrolyte

Battery in prone to its electrolyte decomposition at high temperature as well as materials and electrolyte side effects is increasing; While at low temperature may have electrolyte salting-out and negative SEI film impedance multiplied. The so-called wide temperature electrolyte is make batteries have more broad working environment.

4, security, electrolyte

Battery safety mainly reflected on the combustion and even explosion, first of all, the battery itself is flammable, so when the battery charge and discharge, short circuit, when received the acupuncture, extrusion, when ambient temperature is too high, are likely to cause safety accidents. Therefore, the flame retardant is one of the main secure electrolyte research direction.

Flame retardant function is to add flame retardant additives in conventional electrolyte, generally USES of phosphorus or phosphorus-containing flame retardant, flame retardant additives, the price is reasonable and no damage to the electrolyte performance. In addition, the use of room temperature ionic liquids as an electrolyte has entered a stage of study, also will completely eliminate flammable organic solvents used in the battery. And ionic liquid with low vapor pressure, good thermal stability/chemical stability, non-flammable, etc., will significantly improve the safety of the lithium ion battery.

5, long circular electrolyte

Due to the lithium battery recycling, especially power battery recycling has great technical difficulties, thus improve the battery life is a way to alleviate this situation.

Long circular electrolyte research train of thought, there are two main one is that the stability of the electrolyte, including thermal stability, chemical stability, voltage stability;Second, and the stability of other materials, requirements and electrode film stability, and diaphragm no oxidation, no corrosion and collection of fluid.

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