Potential‐Triggered Multifunctional Additive for Ultrafast‐Charging High‐Voltage LiCoO 2 Batteries

Lithium cobalt oxide (LCO) is widely used for its high volumetric energy density (>700 Wh L −1 ), yet structural degradation at high voltages hampers further energy‐density gains. This paper demonstrates that low highest occupied molecular orbitals (HOMO) level additives can also effectively regulate high‐voltage interface reaction behavior, thereby establishing a new cognitive framework for high‐voltage additive design. Accordingly, multifunctional additive methanesulfonylacetonitrile (MSAN) is introduced for high‐voltage batteries. Once the potential reaches a threshold, MSAN participates in the interfacial reaction in a controlled manner, thereby forming electrode/electrolyte interfaces that combine robustness with fast reaction dynamics. Additionally, MSAN can also further ensure interface stability by capturing and clearing HF. Therefore, Li‐LCO cells with MSAN exhibited a 50C charge–discharge capability, and after 1000 cycles under a 5C discharge condition, it still maintains a capacity retention of 94.3%. MSAN delivers excellent electrochemical performance in both 1.2 Ah Gr‐LCO and high‐energy‐density 3 Ah Li‐LCO pouch cells (457 Wh kg −1 ). These findings provide transformative insights for the design of high‐voltage battery additives.