Atomic layer deposition of ultrafine Pd nanoparticles for enhancing the rate capability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode

Atomic layer deposition(ALD)technology has been adopted to obtain the ultrathin coating layer on the surface of LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM)cathode materials.However,the as-reported coating materials usually form dense film layers and present low electronic conductivity,leading to poor electrochemical kinetics.Herein,the ultrafine Pd nanoparticles(~5 nm)with superior electronic conductivity are successfully deposited on the surface of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)particles by ALD technology.Benefiting from its high electrical conductivity,intrinsic electrochemical inertia to Li+and HF,unique point coating,and the interfacial Pd-O bond,the coating of ultrafine Pd nanoparticles significantly weakens the electrochemical polarization and enhances the rate capability of NCM811 cathode.The capacity retention ratio at 1 C after 100 cycles reaches 84.6%,and the capacity of 153.5 mA·h·g^(−1) is realized at 5 C.Further research finds that the battery with the coating layer of 5 deposition cycles has a better electrochemical performance than the batteries with 2 and 8 deposition cycles.This work enriches the application of ALD technology in the surface modification of electrode materials and broadens the mind of electrochemical performance enhancement.