| 초록 |
Lithium-ion batteries with superior electrochemical performance, high energy density, fast charging capability, and high power are required as the demand for electric vehicles (EVs). To increase energy density, high loading and nickel-rich NCM (>80% of Ni content) was used as cathode materials. However, nickel-rich cathodes and LiPF6-based electrolytes have critical issues such as TM dissolution, cation mixing, residual lithium, microcracking, and formation of HF which interrupt commercialization of the cathode. To solve these problems, a novel electrolyte additive with silyl-ether moiety is applied. Silyl ether moiety scavenges acidic HF, resulting in suppression of transition metal dissolution. A functional group in novel HF scavenger suppressed gas evolution. Also, a novel electrolyte additive forms LiF poor and polar CEI layer by scavenging HF and suppressing reaction between HF and residual lithium, which inhibits phase transformation of the cathode and improves fast charging performance, thereby cycle retention of NCMA|Graphite full cell was increased at 2.8C/1C cycling compared to the baseline electrolyte. |
