H_2O-Boosted MgProton Collaborated Energy Storage for Rechargeable Mg-Metal Batteries

摘要

Rechargeable magnesium batteries (RMBs) are a kind of energy storagesystem with high safety, low cost, and high volumetric energy density. Ingeneral perception, H_2O will passivate the Mg-metal anode. But herein, acoordination–hydrolysis strategy is developed, in which H_2O can be usedas an additive to produce dissociated H~+. Moreover, MgH~+ energy storagemechanism is discovered on CuSe cathode, which helps the specific capacityand energy density enhance to 480 mAh g~(?1) and 413 Wh kg~(?1), respectively.This coordination–hydrolysis strategy also promotes the conductivity andelectron transfer ability of electrolyte. Consequently, the specific capacity canremain 247 mAh g~(?1) even at 2 A g~(?1). MgH+ energy storage route gets rid ofmassive cathode material, and protons have the smallest size and lightestweight, whose theoretical energy density can reach 4230 Wh kg~(?1). The resultselucidated here provide a new route for energy-dense RMBs.