Thermal restacking of graphene structure to improve lithium-air battery cyclability

• Disruption of physical structure in the Li-air cathode after cycles is observed.
• Two-thirds of initial capacity can be recovered by compacting graphene layers.
• Rearranging the cathode structure help to recover the capacity in the next cycle.

Poor rechargeability is one of major drawbacks of lithium-air batteries. Our study reveals that the accumulation and subsequent removal of reaction products during cycles can lead to a serious disruption and volume expansion of the cathode structure and demonstrates that by restacking and realigning the three phase interface of the cycled cathodes via mild heat treatment results in the enhanced cycle performance by over 200% and reduces the discharge overpotential at the same time. The results stress the importance of maintaining the physical configuration of lithium-air cathodes, and provide a new insight towards pulling out capacity retention of the system by better utilization of the available carbon surface.

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