Lower-voltage plateau Zn-substituted Co3O4 submicron spheres anode for Li-ion half and full batteries

Carbonaceous materials are used as the anode for rechargeable lithium-ion batteries (LIBs), however, li-thium dendrites are easily formed during cycling due to the low lithium insertion potential (similar to 0.1 V versus Li+/Li). As alternative anodes, transition metal oxides based on conversion mechanism have attached much attention. But the high lithiation potential (> 1.0 V vs. Li+/Li) usually leads to a low output voltage and energy density when used in a full cell configuration. Herein, Zn-substituted Co3O4 submicron spheres are successfully synthesized by a facile solvothermal reaction and subsequent calcination method. When used as the anode for LIB, the optimized sample shows a specific capacity of 686 mAh g(-1) at 0.8 A g(-1) after 500 cycles, and a specific capacity of 692.9 mAh g(-1) at a higher current density of 3.2 A g(-1) in a half-cell. Thanks to the controlled Zn substitution, the discharge voltage plateau is 0.16 V lower than that of the pure Co3O4 anode at a current density of 0.4 A g(-1). Further investigation of the 0.5Zn-Co3O4//LiCoO2 full cells also displays a high capacity (400.7 mAh g(-1) after 200 cycles at 0.4 A g(-1)) and an excellent rate capability (658.1 mAh g(-1) at 1.6 A g(-1)) compared with the Co3O4//LiCoO2 full cells. This work confirms that substituting suitable metal elements into sub-micron conversion based anodes can reduce the voltage plateau, which is of great significance for the practical applications in high performance energy storage devices. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study focuses on the utilization of Zn-substituted Co3O4 submicron spheres as anodes for LIBs, demonstrating their capability to reduce voltage plateau and improve capacity and rate performance in high-performance energy storage devices.