Improved Cycling Stability of LiNi0.90Co0.05Mn0.05O2 Through Microstructure Modification by Boron Doping for Li‐Ion Batteries

Abstract Boron‐doped LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathodes are synthesized by adding B 2 O 3 during the lithiation of the hydroxide precursor. Density functional theory confirms that boron doping at a level as low as 1 mol% alters the surface energies to produce a highly textured microstructure that can partially relieve the intrinsic internal strain generated during the deep charging of LiNi 0.90 Co 0.05 Mn 0.05 O 2 . The 1 mol% B‐LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathode thus delivers a discharge capacity of 237 mAh g −1 at 4.3 V, with an outstanding capacity retention of 91% after 100 cycles at 55 °C, which is 15% higher than that of the undoped LiNi 0.90 Co 0.05 Mn 0.05 O 2 cathode. This proposed synthesis strategy demonstrates that an optimal microstructure exists for extending the cycle life of Ni‐rich LiNi 1‐ x ‐ y Co x Mn y O 2 cathodes that have an inadequate cycling stability in electric vehicle applications and indicates that an optimal microstructure can be achieved through surface energy modification.