An alkali metal–selenium battery with a wide temperature range and low self-discharge

Abstract

Selenium (Se)-based materials present an interesting opportunity for rechargeable battery systems. Effective physical and chemical immobilization of Se can inhibit the dissolution of polyselenides and the side reaction between Se anions and carbonate-based electrolytes to improve the electrochemical properties. Here, a sulfur and oxygen co-doped hierarchical porous carbon (SO-HPC) is proposed as an effective reservoir to confine Se. The resulting Se/SO-HPC cathode exhibits significantly high rate capability and excellent cycling stability in carbonate electrolyte for Li/Na/K–Se batteries. Moreover, the performance in a wide temperature range and the self-discharge characteristics are appealing for extended practical application. As a result, the Li–Se cell exhibits outstanding capacities of 394 and 264 mA h g⁻¹ at 0.5C after 400 cycles at temperatures of 50 °C and 0 °C. And the capacities of the electrode material show no decay after a rest period of 150 h under the same temperature conditions.