Simultaneous Stabilization of LiNi0.76 Mn0.14 Co0.10 O2 Cathode and Lithium Metal Anode by Lithium Bis(oxalato)borate as Additive

Wengao Zhao; Lianfeng Zou; Jianming Zheng; Haiping Jia; Junhua Song; Mark H Engelhard; Chongmin Wang; Wu Xu; Yong Yang; Ji-Guang Zhang

doi:10.1002/cssc.201800706

Simultaneous Stabilization of LiNi_0.76 Mn_0.14 Co_0.10 O₂ Cathode and Lithium Metal Anode by Lithium Bis(oxalato)borate as Additive

ChemSusChem. 2018 Jul 11;11(13):2211-2220. doi: 10.1002/cssc.201800706. Epub 2018 Jun 11.

Authors

Wengao Zhao^{1

2}, Lianfeng Zou³, Jianming Zheng¹, Haiping Jia¹, Junhua Song¹, Mark H Engelhard³, Chongmin Wang³, Wu Xu¹, Yong Yang^{2

4}, Ji-Guang Zhang¹

Affiliations

¹ Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington, 99354, USA.
² School of Energy Research, Xiamen University, Xiamen, Fujian, 361005, PR China.
³ Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, 3335 Innovation Boulevard, Richland, Washington, 99354, USA.
⁴ State Key Lab of Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, 361005, PR China.

PMID: 29717541
DOI: 10.1002/cssc.201800706

Abstract

The long-term cycling performance, rate capability, and voltage stability of lithium (Li) metal batteries with LiNi_0.76 Mn_0.14 Co_0.10 O₂ (NMC76) cathodes is greatly enhanced by lithium bis(oxalato)borate (LiBOB) additive in the LiPF₆ -based electrolyte. With 2 % LiBOB in the electrolyte, a Li∥NMC76 cell is able to achieve a high capacity retention of 96.8 % after 200 cycles at C/3 rate (1 C=200 mA g^-1 ), which is the best result reported for a Ni-rich NMC cathode coupled with Li metal anode. The significantly enhanced electrochemical performance can be ascribed to the stabilization of both the NMC76 cathode/electrolyte and Li-metal-anode/electrolyte interfaces. The LiBOB-containing electrolyte not only facilitates the formation of a more compact solid-electrolyte interphase on the Li metal surface, it also forms a enhanced cathode electrolyte interface layer, which efficiently prevents the corrosion of the cathode interface and mitigates the formation of the disordered rock-salt phase after cycling. The fundamental findings of this work highlight the importance of recognizing the dual effects of electrolyte additives in simultaneously stabilizing both cathode and anode interfaces, so as to enhance the long-term cycle life of high-energy-density battery systems.

Keywords: LiBOB; batteries; electrolyte additive; lithium; stability.