How to solve the problem between high nickel materials and electrolyte of lithium-ion battery?

The problem arising from the use of high-nickel materials in combination with electrolytes is complicated to solve and have high technical thresholds. If the company does not have sufficient research and development capabilities, it is difficult to make electrolyte products that match high nickel materials.

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, became The battery The performance of the most critical.

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, it is difficult to achieve high-rate continuous discharge of commercial lithium-ion batteries. The main reason is that the battery ear is extremely hot, and the internal resistance of the battery is too high, which is prone to thermal runaway. Therefore, it is required that the electrolyte can suppress the temperature rise of the battery too fast while maintaining high conductivity. For power batteries, achieving fast charging is also an important direction for the development of electrolytes.

High-power batteries not only require high solid-phase diffusion, nano-imprinting, short ion migration path, thickness of control sheet and compaction, but also put forward higher requirements for electrolyte: 1. High dissociation electrolyte Salt; 2, solvent compounding - lower viscosity; 3, interface control - lower membrane impedance.

3, wide temperature electrolyte

When the battery is at a high temperature, the decomposition of the electrolyte itself and the side reaction of the material and the electrolyte are prone to increase; at low temperatures, electrolyte salt precipitation may occur and the impedance of the negative SEI film may be multiplied. The so-called wide temperature electrolyte is to make the battery have a wider working environment.

4, security, electrolyte

The safety of the battery is mainly reflected in the burning or even the explosion. Firstly, the battery itself is flammable. Therefore, when the battery is overcharged, over discharged, or short-circuited, when the external acupuncture and squeezing are received, when the outside temperature is too high, both can cause a security incident. Therefore, flame retardant is a major direction in the study of safe electrolytes.

The flame retardant function is obtained by adding a flame retardant additive to a conventional electrolyte. Generally, a phosphorus-based or halogen-based flame retardant is used, and the flame retardant additive is required to be reasonably priced and does not impair the electrolyte performance. In addition, the use of room temperature ionic liquids as electrolytes has also entered the research stage, and the use of flammable organic solvents in batteries will be completely eliminated. And the ionic liquid has the characteristics of extremely low vapor pressure, good thermal stability/chemical stability, and non-flammability, which will greatly improve the safety of the lithium ion battery.

5, long circular electrolyte

Due to the current technical difficulties in the recovery of lithium batteries, especially the recovery of power batteries, improving battery life is one way to alleviate this situation.

There are two main research ideas for long-circulating electrolytes. One is the stability of the electrolyte, including thermal stability, chemical stability, and voltage stability. Secondly, the stability with other materials requires stable film formation with the electrode. No oxidation with the diaphragm, no corrosion with the current collector.

The page contains the contents of the machine translation.