Crack resistant pure and Co-doped LiNiO2 cathodes synthesized by nanosheet precursors

High-Ni materials LiNiO2 or LiNi1-xMxO2 (x < 0.1), whose energy density is over 800 Wh kg−1 (discharge capacity >220 mAh g−1, average discharge voltage ∼3.8 V), are promising candidates as cathode for next-generation electric vehicle batteries. However, commercial applications of high-Ni cathodes have been hindered by their fast capacity fading with cycling. Herein, we synthesized a series of high-Ni materials (LiNiO2, LiNi0.95Co0.05O2 and LiNi0.9Co0.1O2) by adopting nanosheet hydroxide precursors. The obtained high-Ni materials with micro-spheres made up of nanorod grains can sustain the large volume deformation and eliminates cracking during charge-discharge. Owing to the hierarchical structure, our as-synthesized high-Ni cathodes exhibit excellent cycling stability up to 4.7 V and under high temperatures, and the corresponding full cells show superior long cycling stability suitable for practical applications, such as 94% and 83% capacity retention after 300 and 500 cycles, respectively for a LiNi0.95Co0.05O2||graphite cell. Overall, this study offers a facile approach to address the poor cycling stability of high-Ni materials.