Constructing interstitial pillar to manipulating interlamination interaction force: Towards high sodium-content P2/O3 intergrowth cathodes

As promising sufficient sodium-ion reservoirs, layered O3-type binary nickel manganese oxides always suffer from terrible structural instability originating from the extraction and insertion of Na atoms. Constructing P2/O3 biphasic composites have been proved to be an effective way for enhancing the cyclability of layered sodium oxide cathodes, which are usually realized through inactive cations substitution and sodium content regulation. Herein, a novel strategy was developed to construct high concentration P2/O3 intergrowth layered cathodes via manipulating the interlayer interaction. Guided by the DFT calculations, the interval [BO4]3+ electriferous groups are beneficial to modulating the interlayer configuration, enhancing the oxygen stability and structural stability of layered oxide cathode. The high sodium-content P2/O3 composite exhibits a superior reversible capacity (159.1 mAh g−1 at 0.2 C, 1 C = 200 mA g−1), distinctive rate capability (75.3 mAh g−1 at 5 C) and excellent cycling stability with a capacity retention of 74.1% after 300 cycles at 1 C within wide potential range of 2.0–4.2 V. The results highlight that the synergetic effect of sufficient-sodium P2/O3 hybrid structure induced by manipulating the interlayer interaction is an effective strategy for achieving electrochemically stable layered cathode material for sodium-ion batteries.