Enabling high performance sodium-ion cathode based on uniform O3-NaNi1/3Fe1/3Mn1/3O2 microspheres

Sodium-ion batteries (SIBs) have received widespread attention, and are regarded as one of the most promising substitutes for lithium-ion batteries in the field of large-scale energy storage. O3 type layered oxides are the mainstream SIBs cathode materials, due to their high specific capacity and low cost. However, the unsatisfied electrochemical properties like cycle stability and rate capability induced by the severe interfacial side reaction and structural failure, significantly impede practical applications. Herein, as a proof of concept, we compared O3-NaNi 1/3 Fe 1/3 Mn 1/3 O 2 cathode materials with spherical (s-NFM) and laminar (i-NFM) mesoscopic morphology to demonstrate the effect of morphological regulation on the electrochemical performance. Our results show that the spherical strategy could effectively reduce the side reactions and enhance the structure stability owing to the specific microspherical structure. As a result, the s-NFM cathode shows impressive electrochemical performance at 0.5C, with a discharge specific capacity of 128.6mAh g −1 and a capacity retention rate of 75.8 % after 200 cycles, which are much better than i-NFM. This study provides a new design for the development of high-performance SIB cathode materials.