A high areal capacity solid-state zinc-air battery via interface optimization of electrode and electrolyte

Abstract

Solid-state zinc-air batteries (SZABs) are regarded as a promising energy source for next-generation wearable electronic devices due to their high theoretical energy density and reliability. However, practical development of solid-state zinc-air batteries is hindered by the low specific areal capacity and poor contact between solid-state electrolyte and electrode caused by zinc passivation and electrolyte aging. Herein, we report a new strategy for optimizing the solid-state electrolyte/electrode interface coupling by combining porous zinc electrode and thermal-sensitive solid-state electrolyte F127 to improve the areal-capacity of solid-state zinc-air batteries. The porous Zn anode prepared by zinc electrodeposition on the zinc substrate is used to alleviate zinc passivation and improve the specific area capacity of SZAB. In addition, to enhance the contact between the solid-state electrolyte and the zinc anode, the F127 surfactant is selected as the solid-state electrolyte due to its fluidity at low temperatures. Benefiting from the porous structure and excellent contact, the SZAB using porous zinc anode and the solid-state electrolyte F127 exhibits high areal capacity of 133 mAh cm−2 at the current density of 4 mA cm−2, which is 100 times higher than that of the solid zinc-air battery using zinc foil as the anode. Moreover, the results show that the use of porous zinc electrodes is conducive to achieving high current discharge, which is critical for the practical application of solid-state zinc-air batteries.