Inhibition of Gas-evolved electrolyte decomposition in cylindrical Li-ion battery cells of Ni-rich layered oxide with a dry coating process without post thermal annealing

Although Ni-rich layered oxide materials widely used as the cathode of lithium-ion batteries (LIBs) possess several interesting properties e.g., high energy density, they encounter severe capacity degradation and intrinsic poor thermal stability concerning the Ni-concentration. Herein, a core-shell-like architecture has been achieved by employing the cost-effective dry particle fusion method without an energy-consuming thermal annealing process with alumina (Al 2 O 3 ) nanoparticles over LiNi 0.8 Mn 0.1 Co 0.1 O 2 or NMC811 and resulting in an intact layer with an average shell thickness of 150–200 nm. Such NMC811@ Al 2 O 3 core-shell exhibits excellent cycling stability compared with pristine NMC811. The chemical lithium diffusion coefficient, as calculated from a galvanostatic intermittent titration technique (GITT) infers that the introduction of Al 2 O 3 coating slightly reduces the lithium diffusivity; however, it limits the active material dissolution, as perceived from post-ICP-OES analysis of the counter electrode. Besides, such modified systems exhibit a significant delay in onset potential related to surface layer decomposition and lattice oxygen release. Therefore, the present investigation concludes that the Al 2 O 3 shell in the NMC811@ Al 2 O 3 not only offers superior electrochemical performance but also exhibits good thermal stability. It could achieve thru a cost-effective and scalable dry-fusion method. • Mechanofusing Al 2 O 3 nanoparticles on NMC811 without post thermal annealing. • Al 2 O 3 -NMC811 strong bond at the interface. • Al 2 O 3 infers metal dissolution and delays lattice oxygen releasing. • NMC811@ Al 2 O 3 core-shell exhibits excellent cycling stability and thermal stability. • Inhibition of Gas-evolved Electrolyte Decomposition.