Suppressing Adverse Effects of redox mediator shuttling in Li-air batteries by using silicon-based anode

Lithium-air batteries (LABs) are highly attractive for their highest energy density among all energy storage systems, but the high reactivity and volumetric variation of lithium metal anode (LMA), as well as the inter-electrode crosstalk (shuttling) by soluble species, e.g. redox mediators (RMs), impose arduous challenges for their practicality. Traditional countermeasures such as LMA protecting structures and solid-state electrolytes (SSEs) increase heft, complexity and cost, diminishing LAB’s core advantage—the ultrahigh energy density. In this work, a high-capacity (1750 mAh g -1 SCC ) silicon-carbon composite (SCC) material was synthesized and used as the anode in a Li-ion air battery, exhibiting superior cyclability (86 cycles under 300 mAh g -1 carbon ) compared to that with LMA (61 cycles), and physical characterizations revealed no deposition of RM on the SCC anode despite the absence of SSEs to prevent shuttling, demonstrating their excellent compatibility. This work showcases the prospects of silicon-based anodes to address LABs’ anode stability issue and improve cell cyclability while retaining most of the energy density.