Controlled Synthesis of SnO₂ Nanostructures as Alloy Anode via Restricted Potential Toward Building High-Performance Dual-Ion Batteries with Graphite Cathode

Dual-ion batteries (DIBs) are considered one of the promising energy storage devices in which graphite serves as a bi-functional electrode, i.e., anode and cathode in the aprotic organic solvents. Unlike conventional lithium-ion batteries (LIBs), DIBs reversibly store the cations and anions in the anode and cathodes during redox reactions, respectively. The electrolyte is a source for both cations and anions, so the choice of electrolyte plays a vital role. In the present work, the synthesis of SnO₂ nanostructures is reported as a possible alternative for graphite anode, and the Li-storage performance is optimized in half-cell (Li/SnO₂) assembly with varying amounts of conductive additive (acetylene black) and limited working potential (1 V vs Li). Finally, a DIB using recovered graphite (RG) fabricated from spent LIB as a cathode and SnO₂ nanostructures as an anode under balanced loading conditions. Prior to the fabrication, both electrodes are pre-cycled to eliminate irreversibility. An in-situ impedance study has been employed to validate the passivation layer formation during the charge-discharge process. The high-performance SnO₂/RG-based DIB delivered a maximum discharge capacity of 380 mAh g⁻¹. The electrochemical performance of DIB has been assessed by varying temperature conditions to evaluate their suitability in different climatic conditions.