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  • In Situ Constructing Ultras...
    Tan, Zhouliang; Li, Yunjiao; Lei, Changlong; Li, Yue; Xi, Xiaoming; Jiang, Shijie; Wu, Feixiang; He, Zhenjiang

    Small (Weinheim an der Bergstrasse, Germany) 20, Številka: 5
    Journal Article

    Planar gliding along with anisotropic lattice strain of single-crystalline nickel-rich cathodes (SCNRC) at highly delithiated states will induce severe delamination cracking that seriously deteriorates LIBs' cyclability. To address these issues, a novel lattice-matched MgTiO (MTO) layer, which exhibits same lattice structure as Ni-rich cathodes, is rationally constructed on single-crystalline LiNi Co Mn O (SC90) for ultrastable mechanical integrity. Intensive in/ex situ characterizations combined with theoretical calculations and finite element analysis suggest that the uniform MTO coating layer prevents direct contact between SC90 and organic electrolytes and enables rapid Li-ion diffusion with depressed Li-deficiency, thereby stabilizing the interfacial structure and accommodating the mechanical stress of SC90. More importantly, a superstructure is simultaneously formed in SC90, which can effectively alleviate the anisotropic lattice changes and decrease cation mobility during successive high-voltage de/intercalation processes. Therefore, the as-acquired MTO-modified SC90 cathode displays desirable capacity retention and high-voltage stability. When paired with commercial graphite anodes, the pouch-type cells with the MTO-modified SC90 can deliver a high capacity of 175.2 mAh g with 89.8% capacity retention after 500 cycles. This lattice-matching coating strategy demonstrate a highly effective pathway to maintain the structural and interfacial stability in electrode materials, which can be a pioneering breakthrough in commercialization of Ni-rich cathodes.