Crystal to non-crystal transformation in a Sn-based MOF anode with long cycle life for lithium storage

Abstract

A tin-based MOF (Sn(HHTP)) was synthesized for lithium storage by incorporating tin (Sn) nodes with a lithium-active ligand (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene), which undergoes a transformation from a crystalline to an amorphous state during charge–discharge cycles. The construction of Sn-based MOFs with Sn–O coordination bonds allows them to effectively accommodate the volumetric changes during lithiation/delithiation processes. Concurrently, this transformation process facilitates the exposure of additional active sites. The Sn(HHTP) anode exhibits exceptional cycling stability with a reversible capacity of 239 mA h g⁻¹ at 2 A g⁻¹ after 1000 cycles, which represents a 228% increase in capacity compared to the eleventh-cycle reversible capacity.