Li-rich Mn-based oxides (LRMO) greatly increase its output energy density due to its additional oxygen redox activity. However, the inherent oxygen loss and irreversible phase transition induce low initial coulombic efficiency and serious voltage decay, further seriously impeding its industrial application. Herein, a near-surface in-situ reconstruction strategy has been proposed, which constructs the oxygen vacancies and spinel phase coating on the surface of single-crystal Li-rich Mn-based oxide (SC-LRMO) concurrently to improve Li+ storage performance via the oxalic acid induction method. Intensive exploration based on structure characterizations demonstrates that such a near-surface in-situ reconstruction strategy not only accelerates the transmission of Li+, but also stabilizes high-voltage redox reactions by trapping the escaping On− within the newly formed spinel phase coating. Impressively, the modified sample exhibit 91.1% capacity retention ratio after 300 cycles, superior to the SC-LRMO (74.5% capacity retention ratio after 300 cycles). Additionally, even at a high cut-off voltage of 5 V, the acid etched sample exhibits significantly enhanced cycling stability, delivering 200 mAh g−1 with a 94% capacity retention ratio after 300 cycles. This surface self-reconstruction strategy provides profound insights into regulating the surface structure of LRMO for high-energy-density lithium-ion batteries.
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