New additives to improve battery energy density -Lithium - Ion Battery Equipment
Xiong Dejun said that driven by government subsidies and end-user mileage concerns, high energy density power batteries have become a hot spot in the market. At present, there are three choices for high energy density power batteries: ternary high voltage with graphite, high nickel with graphite, and high nickel with silicon carbon. As the voltage/nickel content of the power battery becomes higher and higher, the challenge to the electrolyte becomes greater and greater.
The general solution strategy for electrolyte is to select core additives. The negative electrode film forming additives are usually VC and EFC, and the positive electrode is sulfur containing additives PS and RPS. However, the combination of these additives is not enough to meet the performance requirements of high-energy power batteries.
For this reason, New Zebang has developed a new negative electrode film forming additive LDY269, a new positive electrode film forming additive LDY196, LDY2258 and LDY2294. The combination of additives can solve the problem of high energy density. At the meeting, Xiongde special chart data made a detailed comparison between the company's new additives and conventional additives.
In NMC532/AG soft packed battery, LDY269 can reduce DCIR and improve high temperature cycling and storage performance instead of VC; In HV-NMC/AG, LDY196 improved the high temperature cycling performance better than PS and RPS; In HV-NMC/AG, LDY196 formula improved the high temperature cycle and high temperature storage performance of the battery better than PS formula.
Xiong Dejun also gave an example: "Our LDY196 formula is about 240 mAh/g in the customer's NCA/Sio-C system. Under the high temperature environment, the storage retention rate and recovery rate in 60 days and 7 days are above 90%. When LDY196 formula is used in 811 silicon carbon (Si-C) cylindrical battery, the effect is also very good."
"Although the LDY196 formula has received good feedback in the field of high energy density power batteries, our customers also hope that the initial impedance of our products can be reduced. Therefore, in order to meet customer needs, we have developed new film forming additives with lower impedance from the perspective of molecular structure, namely LDY2258 and LDY2294.
Comparing single additives on NCA/Sio-C, it can be seen that the initial impedance of LDY2258 and LDY2294 with the same content is lower than that of LDY196, and the cycle performance is roughly the same. The 60 degree storage capacity retention rate and recovery rate are also slightly improved compared with the new film forming additives.(Lithium - Ion Battery Equipment)
"So the formula of LDY2258 and LDY196 were used in high nickel silicon carbon battery. At the same content, we can see that the initial impedance of the new additive LDY2258 is lower than that of LDY196.
Look at another positive film forming LDY2294. The content of LDY2294 is twice as high as that of LDY196, but it can be seen that the impedance under low temperature environment is still lower than it. The high temperature cycle of the two is roughly the same, which also meets the expectation. "We made a comparison between LDY2294 and LDY196 in NMC811/Sio-C. The content of LDY2294 is twice that of LDY196, and the cycle is roughly the same," Xiong Dejun said.
On the whole, New Zebang has made great progress in the development of high energy density power battery electrolyte. New Zebang's electrolyte formula containing LDY196 has received good feedback from high-end customers in HV-NMC/AG and NMC811 (NCA) silicon carbon cylindrical battery systems.