Improving the stability of LiNi0.80Co0.15Al0.05O2 by AlPO4 nanocoating for lithium-ion batteries

Abstract

Nickel-rich layered materials, such as LiNi0.80Co0.15Al0.05O2 (NCA), have been considered as one alternative cathode materials for lithium-ion batteries (LIBs) due to their high capacity and low cost. However, their poor cycle life and low thermal stability, caused by the electrode/electrolyte side reaction, prohibit their prosperity in practical application. Herein, AlPO4 has been homogeneously coated on the surface of NCA via wet chemical method towards the target of protecting NCA from the attack of electrolyte. Compared with the bare NCA, NCA@AlPO4 electrode delivers high capacity without sacrificing the discharge capacity and excellent cycling stability. After 150 cycles at 0.5 C between 3.0–4.3 V, the capacity retention of the coated material is 86.9%, much higher than that of bare NCA (66.8%). Furthermore, the thermal stability of cathode is much improved due to the protection of the uniform coating layer on the surface of NCA. These results suggest that AlPO4 coated NCA materials could act as one promising candidate for next-generation LIBs with high energy density in the near future.