Rechargeable High-Capacity Antimony-Aluminum Batteries

Rechargeable aluminum batteries are potentially the next generation energy storage systems, while they still suffer from unexpected positive electrodes for high-capacity aluminum batteries. For alleviating the specific capacity, in this study, antimony (Sb) is selected as the positive electrode for aluminum battery for its high theoretical capacity of 660 mAh g(-1). For addressing dissolution issues of active Sb species into the electrolyte during the charge-discharge process, a special electrode design coupled with modified separators, the dissolution of Sb into liquid electrolyte is greatly suppressed. At a current density of 300 mA g(-1), the specific discharge capacity can still reach 100 mAh g(-1) after 1000 cycles, indicating the good long-term stability performance. More importantly, a systematical characterization is conducted to acquire a deep understanding of the energy storage mechanism of the Sb positive electrode. The characterization results from in situ Raman reveals that energy storage process involves the incorporation of AlCl4- into Sb to generate SbCl3/SbCl5. The results apparently highlight the strategies for designing high-performance Al-Sb batteries in a rational route. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.