A Highly Reversible and Low‐Cost Sulfur‐Graphite Dual‐Ion Battery

The development of energy storage systems (ESSs) has received increasing attention due to the environmental degradation and fossil fuel shortage. In this study, a highly reversible sulfur‐graphite dual‐ion battery is developed, in which sulfurized polyacrylonitrile (S@PAN) is used as the anodic material. Compared with a graphite (372 mAh g−1) or aluminum (structural instability) anode in a dual‐ion battery, this anodic material exhibits an excellent structural stability and a high specific capacity during lithiation or delithiation. Statistically, a considerable specific capacity of 750 mAh g−1 when calculated based on the weight of S@PAN over a voltage plateau of ≈2 V with only a 7% capacity loss is achieved after 50 cycles at 100 mA g−1 and shows an attractive rate performance at different current densities. This sulfur‐graphite dual‐ion battery is considered to become a promising ESS candidate.