A regeneration strategy based on synchronous utilization in surface impurities of degradation nickel-rich material

Abstract

The LiNi_0.83Co_0.12Mn_0.05O₂ (Ni-rich NCM) cathode materials have been widely studied owing to their high energy density and excellent rate capability. However, Ni-rich NCM is prone to form large amounts of lithium impurities and causes structural decline, resulting in inconvenient material storage. To this end, Li₄SiO₄/SiO₂ was used as a structural regulator to eliminate the residual lithium and convert the irreversible phase. The Li₄SiO₄/SiO₂ protective coating effectively suppresses the corrosion of the electrolyte by blocking the direct contact between the electrode and the electrolyte, while having a high air stability under the hydrophobic action. In addition, SiO₂ has excellent corrosion resistance, which further enhances the cyclic stability of the material. The obtained regenerated NCM material displayed a great capacity of 198.6 mAh g⁻¹ at 0.3 ​C and long cycling stability (capacity retention of 82.2 ​% after 250 cycles). This simple repair strategy significantly reduces the loss rate in industrial production and enhances the electrochemical performance while achieving material reuse.