Regulating Zn migration and deposition via a coordination-driven modified glass fiber membrane for aqueous zinc-ion batteries

Aqueous zinc ion battery (AZIB) is an important development direction for future energy storage. However, the growth of zinc dendrites in AZIB tends to pierce the membrane during the cycling process, leading to short circuits inside the battery, and the free dendrites reduce the Coulomb efficiency. Herein, we propose a membrane based strategy to alleviate the above problem by easily modifying frequently used glass fiber (GF) membrane through depositing polystyrene sulfonate-zinc complexes. The modified GF membrane (named GF/PSS-ZnCl 2 ) has a reduced pore size and a more uniform pore size distribution, which regulate the uniform diffusion of zinc ions. Under the action of the applied electric field, the uniformly distributed negative sulfonic acid groups guide the zinc ions to be uniformly dispersed on the membrane. The long chains of zinc polystyrene sulfonate attached in the pore size of the membrane establish a fast ion transport channel for the zinc ions, which guides the zinc ions to reach the surface of the electrodes in a uniform and fast manner. The battery with modified membrane maintained up to 1800 h of cycling at a current density of 0.1 mA cm −2 , which is 14 times that of the battery with pristine membrane.