Dry-coated graphite/silicon-MIL-53(Al) composite anodes with enhanced cycling stability for lithium-ion batteries

초록

Graphite/silicon (Gr/Si) composite anodes have attracted significant attention as next-generation anode materials due to their high capacity; however, poor long-term cycling stability remains a critical challenge. In this study, composite anodes were fabricated using a solvent-free spheric coater, and the metal-organic framework (MOF) MIL-53(Al) was introduced as a functional additive. Specifically, 5 wt% MIL-53(Al) was incorporated into the Gr/Si composite (denoted as Gr/Si-M) to enhance structural stability and cycling performance. The electrochemical performance of Gr/Si-M was systematically compared with that of pristine Gr/Si and Gr/Si composites containing 5 wt% Super P. Benefiting from the breathing effect of MIL-53(Al), the Gr/Si-M electrode exhibited superior electrochemical performance, delivering a capacity retention of 86.9 % after 100 cycles at a current density of 0.3C, along with improved structural integrity. Moreover, analysis of the constant-voltage (CV) charge capacity ratio revealed that Gr/Si-M maintained the lowest CV contribution (19.6 % after 100 cycles) compared with Gr/Si-S (20.6 %) and pristine Gr/Si (25.7 %), confirming that MIL-53(Al) effectively mitigates resistance increase during cycling. These results highlight the potential of MIL-53(Al) as an effective additive for stabilizing high-capacity silicon-based anodes and advancing the development of durable lithium-ion batteries.

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