Single‐crystalline Ni‐rich LiNi0.91Co0.06Mn0.03O2 cathode enables durable interfacial stability for high electrochemical performances

Summary Despite the commercialization and tremendous attention of the Ni‐rich LiNiCoMnO2 cathode due to high energy and working voltage, there are still hurdles to be improved. The conventional polycrystalline Ni‐rich LiNiCoMnO2 suffers from decays of specific capacity and energy during long‐term cycling. It originates from more deficiency of oxygen and microcracking, resulting in severe phase transition toward disordered rock salt phase. Herein, single‐crystalline Ni‐rich LiNi0.91Co0.06Mn0.03O2 is successfully prepared to overcome these inherent drawbacks of polycrystalline. Benefiting from reduced specific surface area and grain boundaries, single‐crystalline Ni‐rich LiNi0.91Co0.06Mn0.03O2 outperforms polycrystalline in all electrochemical performances. The single‐crystalline LiNi0.91Co0.06Mn0.03O2 exhibits not only superior cycle stability of 84.7% at 40°C after 100 cycles but also high‐capacity retention of 76.2% under 2 C via improving structural integrity. Therefore, this work reveals that single crystalline can be a breakthrough for stable and high electrochemical performances. Interfacial stability of the single‐crystalline Ni‐rich LiNi0.91Co0.06Mn0.03O2 cathode.