Enhanced reversibility of single crystal Ni-rich cathode materials via Ti doping

Abstract

Single crystal nickel-rich cathodes have been widely studied in the field of lithium-ion batteries (LIBs) due to their high volumetric energy density and good structural/electrochemical stability. However, a larger particle size (∼ 5 µm) prolongs the diffusion path of Li+ and leads to poor rate performance. In this work, a modification strategy of Ti4+ doping was used to prepare single-crystal Ni-rich cathodes LiNi0.88Co0.06Mn0.06O2 with good rate performance. Compared to the polycrystalline Ni-rich cathode, the modified cathodes will have wider lithium channels to strip and embed lithium ions more easily. Concurrently, the secure Ti-O bonds can not only maintain the transition metal layer but also inhibit the “air sensitive effect”. After 100 cycles, the electrochemical performance shows that the modified cathodes with 1 at.% Ti4+ doping have a comparatively high original capacity of 193.8 mAh g − 1 and an upgraded capacity retention of ∼ 93.6 % (2.8–4.3 V) at 1 C. A better rate performance (118.6 mAh g − 1) can be achieved at 10 C. This discovery will provide a good research direction for improving the insufficiency of single crystal nickel-rich cathodes.