A Mg-substituted abnormal P2-NaxTMO2 cathode material with a stoichiometric content of Na up to 1 was developed. Such ultrahigh Na content in the P2-type structure enables an absolute solid-solution reaction with near-zero-strain characteristics.
Various optimization strategies are reviewed and summarized to formulate design principles for layered oxide cathodes for sodium-ion batteries.
The introduction of Cu2+ and Sn4+ ensures the remarkable structure stability of O3-Na0.993Ni0.382Mn0.428Cu0.098Sn0.049O2 to depress the Na+/vacancy rearrangement and P3 → O3′ phase transition, and hence good electrochemical performance.
We reconfigure the sodiation/desodiation process of P3-type layered cathodes by a local symmetry tuning strategy to enhance their stability. The cathodes exhibit long-term cycling stability with a higher capacity retention of 74% after 2000 cycles at 1C.
Due to their cost efficiency and the sustainable availability of sodium resources, sodium-ion batteries (SIBs) are regarded as an economical alternative or additional choice to the well-established lithium-ion batteries (LIBs), particularly within extensive energy storing configurations.