A general approach to construct alien metal atoms (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn) doped in tin-phthalic acid complex for superior lithium storage

Abstract

Tin-based metal organic complexes with breakable coordination bonds, multiple active sites, and high theoretical capacity have attracted wide attentiorials for lithium-ion batteries (LIBs). However, the inferior electrical conductivity and significant volume changes have limited their electrochemical stability and practical application performance. This work proposes a universal doping strategy for the preparation of tin-phthalic acid complexes (Sn-MOF) doped with metal atoms (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn). Metal atoms are uniformly dispersed within Sn-MOF for enhancing electrical conductivity and accommodating appropriate volume expansion, resulting in improved rate capability and cycling stability. Additionally, compared to a series of doped Sn-MOF, Zn-doped Sn-MOF exhibits the most exceptional electrochemical performance with a high reversible capacity of 1131 mAh·g⁻¹ and stable cycling performance at a current density of 0.5 A·g⁻¹, delivering a capacity of 1065 mAh·g⁻¹ after 500 cycles. Zn-doping catalyzes the lithiation reaction between Sn-MOF and Li⁺, promoting their reaction kinetics during the first cycle. Furthermore, the Zn-doped Sn-MOF is inclined to form a thin and stable solid electrolyte interface film to maintain cyclic stability.

Graphical Abstract