Mn/Ni-Based Core–Shell Particle Composites with Superior Rate and Cycling Performance for Li/Na-Ion Storage

Rational design of high-performance anode materials is critical to advancing the development of high-energy-density lithium-ion batteries (LIBs) and low-cost sodium-ion batteries (SIBs). Herein, a micro/nanoscale core–shell particle of Mn/Ni–Co 2 O 4 (MNCO) composite with abundant multivalent active sites is fabricated via a facile one-pot hydrothermal route with annealing. Compared with MnCo 2 O 4 (MCO) and NiCo 2 O 4 (NCO), the MNCO composite exhibits enhanced specific capacity, rate capability, and long-cycle stability as an anode, maintaining a reversible capacity of ∼560 mAh g –1 after 2000 cycles at 1 A g –1 for LIBs, and achieving a surface capacitive-dominated charge storage mechanism for SIBs. Its superior performance stems from the dual-phase synergistic effect and hierarchical porous core–shell structure, which accelerate electrochemical kinetics and alleviate volume variation during cycling. This work provides a feasible strategy for developing high-performance metal oxide anode materials.