Solid solution reaction enhanced rapid sodium ion Migration for superior Low-Temperature performance

Owing to the natural abundance of sodium resources, sodium-ion battery (SIBs) systems have emerged as highly promising alternatives for next-generation energy storage applications, particularly for large-scale grid storage and cost-sensitive implementations. The electrochemical performance exhibit pronounced temperature dependence, especially for capacity retention, cycling stability, and operational safety. Both elevated and sub-ambient temperature conditions can induce various detrimental effects that markedly compromise cell performance and longevity. Considerable difficulties of sodium-ion batteries (SIBs) behavior in subzero environments have become a critical challenge in pursuit of more reliable and versatile energy storage solutions. In this study, we fabricated layer cathode materials via a facile sol-gel method, incorporating a synergistic Cu/Co/Mg multi-doping strategy to optimize electrochemical performance, resulting in a high capacity and structurally stable Na_0.7Ni_0.25Cu_0.1Co_0.05Mg_0.05Mn_0.55O₂ (NNCCMM) at 2.0-4.0 V. NNCCMM exhibits extraordinary cycle stability and fast charging capability at low temperatures as well as normal temperature. The capacity at -20°C remains as high as 81.7 % (0.2C) of its room-temperature value. This study significantly expands the potential applications of sodium-ion battery technology while providing critical insights for developing advanced cathode materials with enhanced low-temperature performance.