Simultaneous Li2MoO4 coating and Mo6+ doping improves the structural stability and electrochemical properties of nickel-rich LiNi0.83Co0.11Mn0.06O2

The transition metal oxide (MoO 3 ) reacted with residual Li on the surface of nickel-rich LiNi 0.83 Co 0.11 Mn 0.06 O 2 (NCM831) particles to form Li 2 MoO 4 and successfully coated the particle surface of the cathode materials, thereby easing the reaction between the electrode and electrolyte. In addition, Mo 6+ was doped in the inner part of particles, thus improving the electrochemical properties of cathode material. • MoO 3 reacted with residual Li on the surface of nickel-rich NCM particles to form Li 2 MoO 4 , and Mo 6+ was doped in the inner part of particles to improve t structure of the cathode material. • Using first-principles theoretical calculations to determine changes in the conductive properties of LiNi 0.83 Co 0.11 Mn 0.06 O 2 following doping with Mo 6+ . • Various test techniques were used to analyze the differences between the modified samples and bare sample before and after cycling. • Using ex situ to analyze the change of lattice oxygen for bare sample and modified samples during charging. High-nickel ternary material LiN ix Co y Mn 1-x-y O 2 (NCM) as a cathode material of Li-ion batteries has already been applied in many fields, like electric vehicles and 3C, due to its low cost and outstanding energy storage performance. but fast capacity decays result from interfacial degradation and internal destruction of the NCM structure leading to poor cycle life during charge–discharge processes, hindering widespread application. To solve these problems, this work develops a modification scheme to achieve the one-step generation of a Li 2 MoO 4 coating on the outside of LiNi 0.83 Co 0.11 Mn 0.06 O 2 particles and dope high-valence cations (Mo 6+ ) inside LiNi 0.83 Co 0.11 Mn 0.06 O 2 while reducing the residual Li content on the outside of materials. At 1C(1C = 200mAhg −1 ), the modified sample, Mo + NCM-1.0 (1.0 mol% doped LiNi 0.83 Co 0.11 Mn 0.06 O 2 ), exhibits an excellent discharge capacity of 202 mAhg −1 and cycling stability with a capacity retention of 90.22%. By contrast, pristine LiNi 0.83 Co 0.11 Mn 0.06 O 2 shows the discharge capacity is 189.27 mAhg −1 with a capacity retention of 87.93%. Further research shows that the modification scheme can alleviate the electrode loss during cycling, stabilize the internal structure of the NCM, enhance the Li + diffusion rate, and improve the electrochemical properties. This modification strategy can be applied to other cathode materials.