A Facile Preparation of λ-MnO2 as Cathode Material for High-Performance Zinc-Manganese Redox Flow Battery. Issue 4 (24th February 2020)

• Record Type: Journal Article
• Authors: Liu, Nana; K., Mohanapriya; Pan, Junqing; Hu, Yan; Sun, Yanzhi; Liu, Xiaoguang
• Is Part Of: Journal of the Electrochemical Society. Volume 167:Issue 4(2020)
• Publication Date: 2020-02-24
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ab75c2
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Aqueous-based rechargeable zinc-manganese redox flow batteries have displayed a great advantage in the field of large-scale energy storage due to low cost of zinc and manganese resources and environmentally-safe. Various types of MnO2, including α and δ have been proposed as cathode material, but low capacity and cycling life limited their large scale application. Herein, we report highly crystalline, spinel-type λ -MnO2 as cathode for zinc-manganese (Zn/ λ -MnO2 ) redox flow battery system which derived from LiMn2 O4 via mild acid treatment. This system exhibits diffusion controlled insertion mechanism of Li + in λ -MnO2 spinel structure with little contribution of surface controlled process in 1 M Li2 SO4 + 1 M ZnSO4 electrolyte. The obtained λ -MnO2 cathode delivers two high discharge voltage platforms of 1.97 and 1.81 V with specific capacity of 128 mAh g −1 at a current rate of 2 C under the operating potential window of 1.5–2.1 V. The assembled battery system exhibits excellent rate performance and cyclic stability with high capacity retention of 83% after 1, 000 continuous cycles at a high current density of 10 C. This mechanism enables an outstanding energy efficiency of 98% and provides key insights for the development of high-performance, low-cost and reversible zinc-manganese redox flow batteries.