Laser-induced oxygen vacancy defect Mn7O13.5H2O as binder-free cathode for high performance all-in-one zinc-ion battery

Reachable Zinc ion batteries (ZIBs) are regarded as promising large scale energy storge systems because of their advantages of high safety, high energy density (high volumetric capacity), and economic benefits. However, ZIBs suffer from of lack of suitable cathode materials with high capacity and long stability of circulation. In addition, conventional coating process to prepare cathode with binder (PVDF/PTFE et al.) will not only reduce active material loading but also hinder ion transmission. Hence, a simple binder-free cathode prepare process was proposed. We use laser irradiation the Mn7O13.5H2O/graphene oxide cathode. The laser irradiation will induce vacancy defect in the Mn7O13.5H2O, leading to more active contact sites. Finally, the prepared materials achieve an ultra-high specific capacity of 411.6 mAh g-1 (0.2 A g- 1), an excellent rate performance (176.3 mAh g-1 at a current density of 5 A g-1), and a satisfactory capacity retention rate of 90.1% after long 3500 cycles at 2 A g-1. The assembled all-in-one architecture battery has a fair specific capacity of 177.3 mAh g-1 at the current density of 2 A g-1. This work opens up a new horizon for conveniently preparing binder-free cathode materials with defects for high energy density and long cycle life.