Abstract:Sodium ion (Na⁺)-doped Li_1-xNa_xNi_1/3Co_1/3Mn_1/3O₂ (NCM-Na) cathode materials with enhanced stability were synthesized using a co-precipitation method. The results demonstrate the feasibility of extracting nickel from low nickel matte as a nickel source for synthetic raw materials. Subsequently, the optimal content of Na⁺ is introduced in advance to occupy partially lithium-ion sites in NCM (Ni, Co, Mn) materials synthesized by chemical reagents, which achieves a stable structure with lower Li⁺/Ni²⁺ mixing and improved electrochemical performance. When the dopant content of Na⁺ is 1 wt.% (x=0.01), the capacity retention ratio of the produced NCM-Na cathode increases from 76.84% to 89.21% after 100 cycles (at 1C). In particular, a specific capacity of 110 mA·h·g^-1 is maintained after 200 cycles (at 5C). These results demonstrate that coupling materialization metallurgy and heteroatomic doping are promising strategies for the development of low-cost and high-performance LiNi_1/3Co_1/3Mn_1/3O₂ cathodes for advanced lithium-ion batteries.

Key words: lithium-ion batteries; LiNi_1/3Co_1/3Mn_1/3O₂ cathode; Na⁺-doping; diffusion kinetics; low nickel matte