Single‐crystalline Ni‐rich LiNi 0 . 91 Co 0 . 06 Mn 0 . 03 O 2 cathode enables durable interfacial stability for high electrochemical performances

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.