Bis(neopentyl glycolato)diboron as A Cathode Stabilizer Additive for High-Voltage Lithium-ion Batteries

Bis(neopentyl glycolato)diboron (BNGDB) is used as a electrolyte additive to improve the stability of commercialized lithium ion batteries operating at a high charging-cutoff voltage. Adding of BNGDB lowers the oxidation potential of the electrolyte, which will lead to the formation of a uniform, stable, and low resistance cathode solid electrolyte interphase (CEI) on the cathode surface. This CEI film can suppress the loss of electrolyte by preventing further reaction between electrolyte and cathode material (LiNi0.6Co0.2Mn0.2O2), which improves cyclic stability and discharge capability of LiNi0.6Co0.2Mn0.2O2/graphite pouch cells. With 0.5 wt% BNGDB addition, the pouch cell demonstrate a discharge capacity retention of 83.2% after 200 cycles in base electrolyte. This work brings new insight into the role of additives in electrolytes and can guide the design of more versatile electrolytes for commercialized lithium-ion batteries.