Ti1.1V0.7Cr Nb1.0Ta0.6C3T high-entropy MXene freestanding films for charge storage applications

Abstract

High-entropy (HE) MXenes are a new emerging class of materials with unique properties, diverse compositions, and potential uses in energy storage devices. Herein, high-entropy MXene, Ti1.1V0.7CrxNb1.0Ta0.6C3Tz (Tz = –F, –O, –OH), freestanding films are prepared and tested as electrodes for Zn-ion hybrid supercapacitors (ZHSC), delivering a capacity up to 77 mAh g−1 (245 mAh cm−3) at 0.5 A g−1 with a capacity retention of 87% after 10,000 cycles. This promising performance in ZHSC is achieved when using Zn(CF3SO3)2 or low-cost ZnCl2 solutions. Furthermore, HE MXene films can be used as a negative electrode for Li-ion batteries with a capacity up to 126 mAh g−1 (400 mAh cm−3) at 0.01 A g−1. This report sheds light on the use of a new class of MXene films for various charge storage applications.