MXene-based hybrid architectures for potassium-ion and aluminium-ion battery systems: Design strategies and mechanism insights

Abstract

Potassium-ion batteries (KIBs) and aluminium-ion batteries (AIBs) emerge as viable alternatives to lithium-ion systems, owing to the abundance, cost-effectiveness, and environmental advantages of potassium and aluminium. On the other hand, the development of anode materials lags behind advances in cathode materials. Conventional carbon-based and metal-composite anodes often exhibit low electrochemical activity and undergo significant volume changes. We have explored MXene-based compounds as potential anode materials for KIBs and AIBs. Strategies for producing high-quality MXenes with adjustable surface terminations and controlled layer thickness are the key factors that influence electrical conductivity, ion coordination and interlayer spacing, have been discussed in detail. We also highlight the ion-insertion mechanisms and transport kinetics of K+ and Al3+ within MXene interlayers, comparing their behaviour with that of traditional anodes. This systematic review tries to establish a baseline for performance benchmarking of MXene electrodes against state-of-the-art alternatives across both electrochemical and morphological parameters. The review offers insights into MXene anodes for future KIBs and AIBs, covering their synthesis, surface modification and energy storage behavior.