Synthesis of a fine LiNi0.88Co0.09Al0.03O2 cathode material for lithium-ion batteries via a solvothermal route and its improved high-temperature cyclic performance

Abstract

Nickel–Cobalt–Aluminum (NCA) cathode materials for lithium-ion batteries (LIBs) are conventionally synthesized by chemical co-precipitation. However, the co-precipitation of Ni²⁺, Co²⁺, and Al³⁺ is difficult to control because the three ions have different solubility product constants. This study proposes a new synthetic route of NCA, which allows fabrication of fine and well-constructed NCA cathode materials by a high temperature solid-state reaction assisted by a fast solvothermal process. The capacity of the LiNi_0.88Co_0.09Al_0.03O₂ as-synthesized by the solvothermal method was 154.6 mA h g⁻¹ at 55 °C after 100 cycles, corresponding to 75.93% retention. In comparison, NCA prepared by the co-precipitation method delivered only 130.3 mA h g⁻¹ after 100 cycles, with a retention of 63.31%. Therefore, the fast solvothermal process-assisted high temperature solid-state method is a promising candidate for synthesizing high-performance NCA cathode materials.