Stabilizing the interphasial layer of Ni-rich cathode and graphite anode for lithium ion battery with multifunctional additive

• Published in: Journal of power sources Vol. 467; p. 228343
• Main Authors: Li, Zifei, Lin, Xiuyi, Zhou, Hebin, Xing, Lidan, Lan, Guangyuan, Zhang, Wenguang, Chen, Jiawei, Liu, Mingzhu, Huang, Qiming, Li, Weishan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2020
• Subjects: Electrolyte/electrode interphase; Lithium-ion batteries; Multifunctional electrolyte additive; Nickel-rich cathode; P-toluenesulfonylmethyl isocyanide; Lithium-ion batteries; Multifunctional electrolyte additive; P-toluenesulfonylmethyl isocyanide; Nickel-rich cathode; Electrolyte/electrode interphase
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2020.228343

As a promising cathode candidate in high energy density lithium-ion batteries, Nickel-rich cathode LiNi0.8Co0.15Al0.05O2 (LNCAO) has received extensive attention for its high specific capacity and low cost, while it is subject to fast capacity fading due to the inferior interphasial stability. This work aims to improve the cyclic stability of LNCAO cathode by using a multifunctional electrolyte additive, p-toluenesulfonylmethyl isocyanide (TOSMIC). DFT calculation shows that the high reduction activity of TOSMIC additive is mainly contributed by its sulfone group, while the high oxidation activity is primarily caused by its phenyl group. The obtained experimental results indicate that TOSMIC simultaneously generates effective cathode electrolyte interphase and solid electrolyte interphase layer on LNCAO and graphite surface, respectively, leading to greatly enhanced cyclic stability of LNCAO cathode and increased rate performance of graphite anode. On the other hand, application of TOSMIC could suppress the hydrolyzation reaction of LiPF6, and therefore, hindering the generation of harmful product HF and dissolution of transition metal from LNCAO cathode during cycling. Application of such multifunctional electrolyte additive significantly improves the cycle life of the LNCAO/graphite full cell. [Display omitted] •TOSMIC is proposed as a multifunctional electrolyte additive for LIBs.•Oxidative-decomposition of TOSMIC generates protective film on Ni-rich cathode.•Reductive-decomposition of TOSMIC creates low-resistance film on graphite anode.•TOSMIC hinders the hydrolysis reaction of LiPF6 and the generation of HF.•Effect of each functional group on the performance of TOSMIC is proposed.