An Ultrahigh‐capacity Dual‐ion Battery Based on the Free‐standing Graphite paper cathode and Flower‐like Heterojunction Anode of Tin Disulfide and Molybdenum Disulfide

Dual-ion batteries have been considered as a competitive energy storage device. However, owing to the lack of the suitable high-capacity density and rapid-charging kinetics electrode materials, designing a cost-effective and high performance dual-ion battery is still a great challenge. Herein, an ultrahigh-capacity dual-ion battery is constructed based on the SnS2-MoS2@CNTs heterojunction anode and high crystallinity free-standing graphite paper serves as cathode. The SnS2-MoS2@CNTs heterojunction consisted of ultrathin nanosheets is prepared via a facile two-step hydrothermal method, and shows flower-like morphology and high crystallinity. Benefiting from the unique design concept, the Graphite paper/SnS2-MoS2@CNTs dual-ion battery delivers a high capacity of 274.2 mA h g-1 at 100 mA g-1 and keeps an outstanding capacity retention of 95% after 300 cycles under 400 mA g-1. Even at a high current density of 2 A g-1, the battery still retains a considerable capacity of 112.3 mA h g-1. More importantly, the battery shows an extremely low self-discharge of 0.006% h-1 after resting for 24 h. The characterization of SEM and XRD further demonstrate the excellent cycling stability and good reversibility. Consequently, this constructed dual-ion battery could be a promising energy storage device and provide new insight for the design of high-performance dual-ion batteries.