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.
An ionic potential modulation strategy is devolved to produce a lattice-stable layered oxide by implanting low-ionic-potential cations into the TM and Na layers, achieving an excellent rate capability of up to 50 C and a long-term stability in SIBs.
Through the electrochemical ion-exchange method, P2-K0.56Na0.11Li0.12Ni0.22Mn0.66O2 was successfully synthesized as a high-performance cathode with a single-phase reaction and K+/vacancy disordering for potassium-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.
Various optimization strategies are reviewed and summarized to formulate design principles for layered oxide cathodes for sodium-ion batteries.