Spatially confined transition metals boost high initial coulombic efficiency in alloy anodes

• Published in: Chemical science (Cambridge) 2024-12, Vol.16 (1), p.418-424
• Main Authors: Fu, Haoyu, Gu, Fangchao, Niu, Yize, Liao, Shuxuan, Bu, Zeyuan, Wang, Haonan, Yang, Dong, Wang, Xiaoshan, Li, Qiang
• Format: Article
• Language: English
• Subjects: Anodes; Chemistry; Decomposition reactions; Density functional theory; Electrochemical analysis; Energy conversion efficiency; Lithium oxides; Lithium-ion batteries; Magnetic measurement; Multilayers; Nickel oxides; Reaction kinetics; Silicon dioxide; Tin dioxide; Transition metal alloys; Transition metal oxides
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d4sc06323f

Alloy-type materials hold significant promise as high energy density anodes for lithium-ion batteries. However, the initial coulombic efficiency (ICE) is significantly hindered by the poor reversibility of the conversion reaction and volume expansion. Here, the NiO/SnO 2 multilayers with a hybrid interface of alloy and transition metal oxides are proposed to generate Ni nanoparticles within confined layers, catalyzing Li 2 O decomposition and suppressing the coarsening of Sn or Li 2 O particles. Supported by density functional theory (DFT) calculations and revealed by operando magnetometry, the spatially confined, well maintained Ni active sites lower the energy barrier for Li-O bond rupture and enhance the migration dynamics of Li + . The enhanced reaction kinetics lead to achievement of an impressive ICE of 92.3% and a large capacity of 1247 mA h g −1 with 97% retention after 800 cycles. Furthermore, the NiO/SnO 2 anode exhibits excellent electrochemical performances in both Na/K-ion batteries. Notably, when constructed with the same framework, SiO 2 also delivers significantly improved lithium storage properties with ultra-high ICEs. This work paves the way for advanced designs of alloy-type anodes that satisfy both ICE and overall electrochemical performance. The NiO/SnO 2 hybrid interface generates Ni nanoparticles within multilayers, catalyzing Li 2 O decomposition and suppressing Sn or Li 2 O particle coarsening, thus enhancing reaction kinetics to achieve ultra-high ICE, capacity and long cycling.