MBene with Redox‐Active Terminal Groups for an Energy‐Dense Cascade Aqueous Battery

Abstract

Two‐dimensional (2D) transition metal borides (MBenes), new members of the 2D materials family, hold great promise for use in the electrocatalytic and energy storage fields because of their high specific area, high chemical activity and fast charge carrier mobility. Although various types of MBenes have been reported, layered MBenes featuring redox‐active terminal groups for high energy output have not yet been produced. We present a facile and energy‐efficient method for synthesizing MBenes equipped with redox‐active terminal groups for cascade Zn||I2 batteries. Layered MBenes have ordered metal vacancies and –Br terminal groups, enabling the sequential reactions of I–/I0 and Br–/Br0. The I2‐hosting MBene‐Br cathode results in a specific energy as high as 485.8 Wh kg–1 at 899.7 W kg–1 and a specific power as high as 6007.7 W kg–1 at 180.2 Wh kg–1, far exceeding the best records for Zn||I2 batteries. The results of this study demonstrate that the challenges of MBene synthesis can be overcome and reveal an efficient path for producing high‐performance redox‐active electrode materials for energy‐dense cascade aqueous batteries.This article is protected by copyright. All rights reserved

Novel Two-Dimensional MBenes: Synthesis, Properties, and Energy Storage and Electrocatalytic Applications of Two-Dimensional Metal Borides

“…These values significantly surpass previous benchmarks for Zn||I 2 batteries. The findings underscore the surmountability of synthesis challenges associated with MBenes and unveil a promising avenue for generating redox-active electrode materials of high-performance crucial for energy-dense cascade aqueous batteries. , …”