Boosting the Electrochemical Storage Properties of Co3O4 Nanowires by the Mn Doping Strategy with Appropriate Mn Doping Concentrations

Jun Wang; Huifang Zhang; Haoyan Duan; Heming Zhao; Juncheng Qi; Boxiang Ma; Honghui Fan

doi:10.1021/acsomega.3c08650

Boosting the Electrochemical Storage Properties of Co₃O₄ Nanowires by the Mn Doping Strategy with Appropriate Mn Doping Concentrations

ACS Omega. 2024 Feb 2;9(6):6955-6964. doi: 10.1021/acsomega.3c08650. eCollection 2024 Feb 13.

Authors

Jun Wang¹, Huifang Zhang¹, Haoyan Duan², Heming Zhao¹, Juncheng Qi³, Boxiang Ma¹, Honghui Fan¹

Affiliations

¹ College of Mechatronics Engineering, North University of China, Taiyuan 030051, P. R. China.
² China North Standardization Center, Beijing 100089, P.R. China.
³ School of Information and Communication Engineering, North University of China, Taiyuan 030051, P. R. China.

Abstract

High specific capacitance, high energy density, and high power density have always been important directions for the improvement of electrode materials for supercapacitors. In this paper, Co₃O₄ nanowire arrays with various Mn doping concentrations (Mn:Co molar ratio = 1:11, 1:5, 1:2) directly grown on nickel foam (NF) were prepared by a simple hydrothermal method and annealing process. The influence of Mn doping on the morphology, structure, and electrochemical behaviors of Co₃O₄ was investigated. The results show that partial substitution of Co ions with Mn ions in the spinel structure does not change the nanowire morphology of pure Co₃O₄ but increases the lattice parameter and decreases the crystallinity of cobalt oxide. Electrochemical measurements showed that Mn doping in Co₃O₄ could effectively enhance the redox activity, especially Co₃O₄ with a Mn doping ratio of 1:5, which exhibits the most excellent electrochemical performance, with the maximum specific capacitance of 1210.8 F·g^-1 at 1 A·g^-1 and a rate capability of 33.0% at 30 A·g^-1. The asymmetric supercapacitor (ASC) device assembled with the optimal Mn-Co₃O₄ (1:5) and activated carbon (AC) electrode performs a high specific capacitance of 105.8 F·g^-1, a high energy density of 33 Wh·kg^-1 at a power density of 748.1 W·kg^-1, and a capacitance retention of 60.2% after 5000 cycles. This work indicates that an appropriate Mn doping concentration in the Co₃O₄ lattice structure will have great potential in rationalizing the design of spinel oxides for efficient electrochemical performance.