Novel dual-phase porous Mn2O3/(co,Mn)(co,Mn)2O4 composite cathode material with enhanced interfacial stability for ultra-long cycle life in zinc ion batteries

Aqueous zinc-ion batteries (AZIBs) are considered highly promising next-generation energy storage technologies due to their intrinsic safety, low cost, and high theoretical capacity. Among the potential cathode materials for AZIBs, manganese oxide stands out because of its high theoretical specific capacity, diverse crystal structures, and abundant crustal availability. However, drawbacks of manganese oxide including irreversible phase transitions, low ionic conductivity, and unavoidable Mn 3+ dissolution often result in low capacity and poor cycling stability. Herein, a novel dual-phase material, Mn 2 O 3 /(Co,Mn)(Co,Mn) 2 O 4 (MO/CMO), featuring a meso porous structure and stable phase interface, was facilely synthesized via one-step thermal decomposition of Co 2+ -doped MnCO 3 precursors. The meso pores provide additional active sites, facilitating faster reaction kinetics, while the phase interface effectively suppresses spontaneous Mn 3+ dissolution, resulting in excellent cycling stability. Specifically, the MO/CMO-10 cathode in aqueous electrolyte cell exhibits a high initial specific capacity of 253 mAh g −1 at 0.1 A g −1 , and enhanced cycling stability of 98 mAh g −1 after 2200 cycles at 1.0 A g −1 and an ultra-long cycle life of 63 mAh g −1 over 6800 cycles at 2.0 A g −1 . When assembled in flexible quasi-solid-state ZIBs, the cell maintains a high specific capacity of up to 124 mAh g −1 after 980 cycles at 1.0 A g −1 . Remarkably, the pouch cell sustains stable output even under harsh conditions, indicating promising potential for wearable applications.