Trace MXene Electrolyte Additives for High-Performance Zinc Anodes

The stability of electrode materials during the operation of Aqueous zinc-ion batteries (AZIBs) is one of the key factors affecting battery performance. The growth of zinc dendrites not only leads to the destruction of the internal structure of the battery but also may cause safety issues such as short circuits. In this work, MXene was selected as an electrolyte additive to form a MXene buffer layer on the anode surface and regulate the uniform deposition of Zn2+ to protect the stability of the zinc anode. The MXene buffer layer not only effectively isolates the electrolyte from the zinc anode to prevent the occurrence of corrosion reactions, but also guides the formation of a uniform deposition layer of Zn2+. The symmetric battery assembled with the electrolyte containing MXene can stably cycle for nearly 1000 h at 5 mA cm–2, and the full battery assembled from it still has a specific capacity of 201.19 mA h g–1 after 500 cycles at a current density of 1 A g–1, which is 1.6 times the specific capacity (122.52 mA h g–1) of the battery assembled with ZnSO4 as the electrolyte. This study develops an electrolyte additive that can not only regulate the uniform deposition of zinc ions but also take advantage of its conductivity to promote rapid electron transfer.