The theoretically high energy densities and wide availability of active materials have led to great interest in the development of magnesium‑sulfur (MgS) batteries. However, poor electronic conductivity of sulfur, active material dissolution, polysulfide shuttling, and poor cycling stability are major challenges that need to be tackled. Herein we observed the pristine MgS cell faces significant overcharging issues and cell failure is common within 30 cycles with significant capacity decay. With the help of XRD and elemental mapping realized that the dissolved liquid polysulfides are metastable in nature. Due to the high sulfophilic nature of the separator, polysulfide absorption leads to slow crystal growth inside the separator. This active material trapping might be the reason for quick capacity decay. We attempted to revive the dissolved polysulfides by introducing conductive nitrogen-doped graphene (N-gpn)@Carbon cloth(CC) interlayer between the electrodes and separator. This interlayer has a high polysulfide absorption nature, which allows the battery to demonstrate an initial capacity of 1075 mAh g−1 and increased cycling stability to 100 cycles. However, this stability was further enhanced to 300 cycles by protecting the anode. Theoretical considerations suggest that among all polysulfides, MgS8, has the strongest interaction with N-gpn and can be trapped most favorably in a defective N-gpn. This leads to enhanced utilization of the active material and improved cycling stability.
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