Decoupled tin–silver batteries with long cycle life and power output stability based on dendrite-free tin anode and halide insertion cathode chemistry

Abstract

Conventional Ag–Zn batteries have historically faced the challenge of poor cycling stability, rooting in issues associated with Ag cathode dissolution and Zn anode dendrites. Herein, we present a pioneering decoupled Sn–Ag cell, which features two chambers separated by a cation-exchange membrane, containing a dendrite-free Sn metal anode immersed in an alkaline anolyte, and an Ag nanowires/carbon nanotube 3D thick-network cathode in a neutral catholyte. Benefiting from the achieved high electroplating/stripping stability of the metallic Sn anode in the alkaline electrolyte and the electrochemical reversibility of the Ag/AgCl cathode redox couple in the neutral electrolyte, the assembled decoupled Sn–Ag cell demonstrates superior cycling stability, retaining 82.4% of its initial capacity even after 4000 cycles (2 mA cm⁻²), significantly outperforming both the contrastive decoupled Ag–Zn cell (1500 cycles) and conventional alkaline Ag–Zn batteries (<100 cycles). Furthermore, through the integration of the decoupled Sn–Ag battery with solar cells and power management circuits, an intelligent power system of photovoltaic charging and energy storage was designed, demonstrating its practical viability through maintenance-free charging–discharging during day–night cycles. This research not only significantly increases the lifespan of Ag-batteries with an ultra-flat voltage platform but also opens avenues for the decoupled design of a wide variety of aqueous battery systems.