Less Is More: High-Performance All-Solid-State Electrode Enabled by Multifunctional MXene

In all-solid-state batteries, the traditional electrode is assembled with active electrode materials, electronic conductors, and solid electrolytes. This multiple-phase structure with solid–solid contact leads to complicated interface degradations, such as electrolyte decomposition and derived mass/charge transfer obstacle. To ameliorate above issues, the less electrode components are employed, the less interface issue will emerge. Herein, such a conception is implemented by MXene, which not only provides the dual ionic–electronic transport network but also acts as a buffer layer for alleviating volume changes and homogenizing the electric field. The practicability and universality of this multifunctional MXene strategy are verified in intercalation and alloy type anodes, as well as sulfur and selenium cathodes. More excitingly, a thick electrode (∼100 μm) with a high mass loading (16.7 mg cm–2) can even be realized in a germanium/MXene electrode without obvious capacity decay upon cycling. Less MXene turns complexity into simplicity and eventually shows fascinating electrochemical performance in all-solid-state batteries.