Weakly solvated EC-free linear alkyl carbonate electrolytes for Ni-rich cathode in rechargeable lithium battery

Guohuang Kang; Geng Zhong; Jiabin Ma; Rui Yin; Kangning Cai; Tianqi Jia; Xiaolong Ren; Kuang Yu; Peiwu Qin; Zhen Chen; Feiyu Kang; Yidan Cao

doi:10.1016/j.isci.2022.105710

Weakly solvated EC-free linear alkyl carbonate electrolytes for Ni-rich cathode in rechargeable lithium battery

iScience. 2022 Dec 2;25(12):105710. doi: 10.1016/j.isci.2022.105710. eCollection 2022 Dec 22.

Authors

Guohuang Kang^{1

2}, Geng Zhong^{1

2}, Jiabin Ma^{1

2}, Rui Yin¹, Kangning Cai^{1

2}, Tianqi Jia^{1

2}, Xiaolong Ren¹, Kuang Yu^{1

2}, Peiwu Qin^{2

3}, Zhen Chen¹, Feiyu Kang^{1

2}, Yidan Cao^{1

2}

Affiliations

¹ Institute of Materials Research, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
² Tsinghua-Berkeley Shenzhen Institute, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
³ Institute of Biopharmaceutical and Health Engineering, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.

Abstract

Ethylene carbonate (EC) in the electrolyte is not stable in cells operated at high voltage (≥4.4V) or with Li metal anode, which greatly reduce the energy density and lifetime of the rechargeable lithium battery. Herein, an EC-free linear alkyl carbonate-based electrolyte is developed, which enables the high-voltage (≥4.4V) and low-temperature (-30°C) application of Ni-rich cathode (LiNi_0.8Mn_0.1Co_0.1O₂, NCM811). The EC-free system, consisting of LiPF₆ and LiNO₃ in ternary linear alkyl carbonates, possesses low viscosity, weakly solvated structure, and high interfacial stability with both the Ni-rich cathode and the Li metal anode to avoid continuous electrode/electrolyte side reactions and metal dissolution from the cathode. As a result, the Li||NCM811 cell delivers remarkable capacity retention of 93 ± 0.5% at the voltage of 4.4V and 88 ± 0.6% at 4.5V over 100 cycles. This study provides very encouraging perspective to develop EC-free carbonate-based electrolyte for high-voltage and low-temperature application in high-energy-density rechargeable lithium batteries.

Keywords: Electrochemistry; Energy storage; Materials science.