Inhibiting dendrites on Zn anode by ZIF-8 as solid electrolyte additive for aqueous zinc ion battery

Aqueous zinc ion batteries (AZIBs) are considered as one of the most promising alternatives for lithium-ion battery because of its high theoretical capacity, mild reaction with water, high hydrogen evolution potential and abundant natural reserves. However, the growth of anode dendrite and the attenuation of cathode capacity limit the application of zinc ion battery. Here, we propose that ZIF-8 can be used as an electrolyte additive for AZIBs to promote dendrite-free zinc anodic plating/stripping process. The results show that under the action of uniform ionic flux of ZIF-8, the zinc anode achieves a lifetime of more than 550 h, and significantly inhibits the occurrence of positive side reactions (106.1 mAh g−1 after 500 cycles at a current density of 1 A g−1). Density functional theory was used to systematically calculate the binding energy of Zn2+ to different pore sizes of ZIF-8 and the results reveal that the adsorption capacity of ZIF-8 can control the migration of Zn2+. This work expands the application of MOFs in AZIBs and opens up a new door for future research about AZIBs based on MOFs.