Construction of Bi₂O₃/Bi₂S₃ hierarchical heterostructures as advanced multi-ions storage electrodes for fibrous aqueous batteries

Aqueous rechargeable metal-ions (Li⁺, Na⁺, K⁺, Mg²⁺, Al³⁺) batteries are significant for advancing more affordable, safer, and environmentally friendly electrochemical energy storage technologies. However, few electrode materials are able to perform conspicuous, stable and reversible redox reactions in various aqueous electrolytes. Herein, we systematically demonstrated a Bi₂O₃/Bi₂S₃ hierarchical heterostructures electrode material with a nanosheets arrays’ structure which can store more than ten monovalent, bivalent and trivalent metal ions. The capacity of resulting Bi₂O₃/Bi₂S₃ electrode is more than three times that of the pure phase material and exceeds that of other reported multi-ion storage materials. Both experimental and theoretical results show that the construction of hierarchical heterostructures significantly improvs the conductivity and accelerates the ions migration in the Bi₂O₃/Bi₂S₃ electrode. Particularly, the Bi₂O₃/Bi₂S₃ electrode reveals rate capability in 1 M Na₂SO₄ electrolyte, while creating a high reversible capacity of 1.51 mAh cm⁻² at 2.0 mA cm⁻² and 0.74 mAh cm⁻² at 20 mA cm⁻². When coupled with the InHCF cathode, the full fibrous aqueous rechargeable sodium-ion battery delivers a high energy density of 336.97 mWh cm⁻³ at 1.09 W cm⁻³. Our work will stimulate the development of Bi₂O₃/Bi₂S₃ multi-ions storage materials for various high-performance aqueous batteries.