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DOI number:10.1002/adma.74333

Journal:Advanced Materials

Abstract:Phase transitions in sodium layered transition metal (TM) oxides often induce microstrain and TM ion migration, leading to structural degradation and poor cycling stability. However, a rational design approach for optimizing phase transitions is still lacking. Here we introduce phase transition potential (Φphase) as a rational descriptor to predict and control phase evolution in these cathodes. A lower Φphase enables smoother Na+ migration and slower slab sliding during Na extraction, thereby facilitating a continuous phase transformation rather than abrupt phase changes. Guided by this concept, we design a calcium-substituted layered oxide, Na0.96Ca0.02Ni0.33Fe0.33Mn0.33O2 (NCNFMO), which delivers a specific capacity of 140 mAh g−1 at 0.1 C and retains 84.2% of its initial capacity after 500 cycles at 1 C, compared to only 26.4% retention for NaNi0.33Fe0.33Mn0.33O2. Moreover, the NCNFMO||Al@C full cell maintains a high-capacity retention of 82.5% after 100 cycles, and 6.1 Ah full cell demonstrates an energy density of 192 Wh kg−1entire cell. These findings offer fundamental insights into phase behavior-induced microstrain and a promising path toward high-energy, long-life sodium-ion batteries.

Indexed by:Journal paper

Translation or Not:no

Date of Publication:2026-02-06

Links to published journals:https://advanced.onlinelibrary.wiley.com/doi/abs/10.1002/adma.74333