A medium-entropy transition metal oxide cathode for high-capacity lithium metal batteries

Yi Pei; Qing Chen; Meiyu Wang; Pengjun Zhang; Qingyong Ren; Jingkai Qin; Penghao Xiao; Li Song; Yu Chen; Wen Yin; Xin Tong; Liang Zhen; Peng Wang; Cheng-Yan Xu

doi:10.1038/s41467-022-33927-0

A medium-entropy transition metal oxide cathode for high-capacity lithium metal batteries

Nat Commun. 2022 Oct 18;13(1):6158. doi: 10.1038/s41467-022-33927-0.

Authors

Yi Pei^#¹, Qing Chen^#¹, Meiyu Wang², Pengjun Zhang³, Qingyong Ren^{4

5}, Jingkai Qin¹, Penghao Xiao⁶, Li Song³, Yu Chen⁴, Wen Yin^{4

5}, Xin Tong^{4

5}, Liang Zhen^{7

8}, Peng Wang^{9

10}, Cheng-Yan Xu^{11

12}

Affiliations

¹ Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
² National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures and Center for the Microstructures of Quantum Materials, Nanjing University, Nanjing, 210093, China.
³ National Synchrotron Radiation Laboratory, CAS Center for Excellence in Nanoscience, University of Science and Technology of China, Hefei, 230029, China.
⁴ Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.
⁵ Spallation Neutron Source Science Center, Dongguan, 523803, China.
⁶ Department of Physics & Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
⁷ Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China. lzhen@hit.edu.cn.
⁸ School of Materials Science and Engineering, and MOE Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Harbin Institute of Technology, Harbin, 150001, China. lzhen@hit.edu.cn.
⁹ National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Collaborative Innovation Center of Advanced Microstructures and Center for the Microstructures of Quantum Materials, Nanjing University, Nanjing, 210093, China. peng.wang.3@warwick.ac.uk.
¹⁰ Department of Physics, University of Warwick, Coventry, CV4 7AL, UK. peng.wang.3@warwick.ac.uk.
¹¹ Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China. cy_xu@hit.edu.cn.
¹² School of Materials Science and Engineering, and MOE Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Harbin Institute of Technology, Harbin, 150001, China. cy_xu@hit.edu.cn.

^# Contributed equally.

Abstract

The limited capacity of the positive electrode active material in non-aqueous rechargeable lithium-based batteries acts as a stumbling block for developing high-energy storage devices. Although lithium transition metal oxides are high-capacity electrochemical active materials, the structural instability at high cell voltages (e.g., >4.3 V) detrimentally affects the battery performance. Here, to circumvent this issue, we propose a Li_1.46Ni_0.32Mn_1.2O_4-x (0 < x < 4) material capable of forming a medium-entropy state spinel phase with partial cation disordering after initial delithiation. Via physicochemical measurements and theoretical calculations, we demonstrate the structural disorder in delithiated Li_1.46Ni_0.32Mn_1.2O_4-x, the direct shuttling of Li ions from octahedral sites to the spinel structure and the charge-compensation Mn³⁺/Mn⁴⁺ cationic redox mechanism after the initial delithiation. When tested in a coin cell configuration in combination with a Li metal anode and a LiPF₆-based non-aqueous electrolyte, the Li_1.46Ni_0.32Mn_1.2O_4-x-based positive electrode enables a discharge capacity of 314.1 mA h g^-1 at 100 mA g^-1 with an average cell discharge voltage of about 3.2 V at 25 ± 5 °C, which results in a calculated initial specific energy of 999.3 Wh kg^-1 (based on mass of positive electrode's active material).

Abstract

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