Facilitating capacity enhancement of nickel-rich layered oxide via 'pre-expansion' of precursor lattice

Nickel-rich layered oxide emerges as a promising cathode material for high-energy lithium-ion batteries. Expanding the lattice spacing is found to be beneficial for enhancing the electrochemical performance of nickelrich layered oxides. In this study, sodium lignosulfonate is introduced into the coprecipitation process to interfere with the chelation precipitation process of transition metal ions, resulting in a novel lattice spacing expansion strategy. The expansion of the layer spacing significantly improves the storage capacity of the active material. Comparison with the control sample NCM811 reveals that modified sample exhibits a specific discharge capacity of 209.8 mAh g-1, which is superior to the 198.8 mAh g-1 capacity of unmodified NCM811. Importantly, this expansion strategy does not induce adverse effects on the cycle stability of the active material during prolonged cycling. The use of sodium lignosulfonate in the "pre-expansion" strategy does not leave any residue in the precursor, thus ensuring compatibility with other modification strategies. Moreover, the proposed modification