Porous Metal–Organic Frameworks for Enhanced\nPerformance Silicon Anodes in Lithium-Ion Batteries

Abstract

Maintaining\nthe physical integrity of electrode microstructures\nin Li-ion batteries is critical to significantly extend their cycle\nlife. This is especially important for high-capacity anode materials\nsuch as silicon, whose operational volume expansion exerts huge internal\nstress within the anode, resulting in electrode destruction and capacity\nfade. In this study, we demonstrate that by incorporating metal–organic\nframeworks (MOFs) with carboxylate organic linkers into Si-based anodes,\na stable and flexible pore network is generated to maximize and maintain\nLi-ion flux throughout the electrode’s architecture. We show\nthat the zirconium carboxylate MOF UiO-67 is a versatile comaterial\nto boost performance and mitigate the rate of anode degradation that\npresently limits the lifetime of Si anodes. The cage-like pores in\nUiO-67 and flexural properties of the 4,4′-biphenyldicarboxylate\norganic linker are proposed to create robust “ionophores”\nin the anode film to enhance longer term durability and performance.