Wengao Zhao1,2, Jianming Zheng1, Lianfeng Zou3, Haiping Jia1, Bin Liu1, Hui Wang1, Mark Engelhard3, Chongmin Wang3, Wu Xu1, Yong Yang2,4, Ji‐Guang Zhang1
1Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99354, USA
2School of Energy Research, Xiamen University, Xiamen, Fujian 361005, China
3Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, WA 99354, USA
4State Key Lab of Physical Chemistry of Solid Surfaces, and Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen Fujian 361005 China
Tóm tắt
AbstractThe lithium (Li) metal battery (LMB) is one of the most promising candidates for next‐generation energy storage systems. However, it is still a significant challenge to operate LMBs with high voltage cathodes under high rate conditions. In this work, an LMB using a nickel‐rich layered cathode of LiNi0.76Mn0.14Co0.10O2 (NMC76) and an optimized electrolyte [0.6 m lithium bis(trifluoromethanesulfonyl)imide + 0.4 m lithium bis(oxalato)borate + 0.05 m LiPF6 dissolved in ethylene carbonate and ethyl methyl carbonate (4:6 by weight)] demonstrates excellent stability at a high charge cutoff voltage of 4.5 V. Remarkably, these Li||NMC76 cells can deliver a high discharge capacity of >220 mA h g−1 (846 W h kg−1) and retain more than 80% capacity after 1000 cycles at high charge/discharge current rates of 2C/2C (1C = 200 mA g−1). This excellent electrochemical performance can be attributed to the greatly enhanced structural/interfacial stability of both the Ni‐rich NMC76 cathode material and the Li metal anode using the optimized electrolyte.
