Chunlei Jiang

Sodium‐ion batteries (SIBs) are a promising alternative for the large‐scale energy storage owing to the natural abundance of sodium. However, the practical application of SIBs is still hindered by the low working voltage, poor rate performance, and insufficient cycling stability. A sodium‐ion based full battery using a multi‐ion design is now presented. The optimized full batteries delivered a high working voltage of about 4.0 V, which is the best result of reported sodium‐ion full batteries. Moreover, this multi‐ion battery exhibited good rate performance up to 30 C and a high capacity retention of 95 % over 500 cycles at 5 C. Although the electrochemical performance of this multi‐ion battery may be further enhanced via optimizing electrolyte and electrode materials for example, the results presented clearly indicate the feasibility of this multi‐ion strategy to improve the electrochemical performance of SIBs for possible energy storage applications.

Calcium-ion batteries (CIBs) are attractive candidates for energy storage because Ca²⁺ has low polarization and a reduction potential (−2.87 V versus standard hydrogen electrode, SHE) close to that of Li⁺ (−3.04 V versus SHE), promising a wide voltage window for a full battery. However, their development is limited by difficulties such as the lack of proper cathode/anode materials for reversible Ca²⁺ intercalation/de-intercalation, low working voltages (<2 V), low cycling stability, and especially poor room-temperature performance. Here, we report a CIB that can work stably at room temperature in a new cell configuration using graphite as the cathode and tin foils as the anode as well as the current collector. This CIB operates on a highly reversible electrochemical reaction that combines hexafluorophosphate intercalation/de-intercalation at the cathode and a Ca-involved alloying/de-alloying reaction at the anode. An optimized CIB exhibits a working voltage of up to 4.45 V with capacity retention of 95% after 350 cycles.

In this work, an integrated dual‐ion battery design is reported with active materials, current collectors, and separator, assembled in one flexible component. An aluminum film is deposited directly onto one side of the 3D porous glass fiber separator to form a porous anode. Cathode active materials are loaded on the other side of the separator with aluminum film deposited on the top as current collector. This design demonstrates ultrafast charge/discharge rate up to 120 C while maintaining high capacity of 116.1 mA h g⁻¹. Moreover, long‐term stability of over 1500 cycles at a high rate of 60 C is achieved. The estimated energy density remains as high as 232.6 W h kg⁻¹ at an ultrahigh power density of 22634.5 W kg⁻¹.

Hybrid supercapacitors (HSCs) with lithium-ion battery-type anodes and electric double layer capacitor-type cathodes are attracting extensive attention and under wide investigation because of their combined merits of both high power and energy density. However, the performance of most HSCs is limited by low kinetics of the battery-type anode which cannot match the fast kinetics of the capacitor-type cathode. In this study, we have synthesized a three-dimensional (3D) porous composite with uniformly incorporated MoS₂ flocculent nanostructure onto 3D graphene via a facile solution-processed method as an anode for high-performance HSCs. This composite shows significantly enhanced electrochemical performance due to the synergistic effects of the conductive graphene sheets and the interconnected porous structure, which exhibits a high rate capability of 688 mAh/g even at a high current density of 8 A/g and a stable cycling performance (997 mAh/g after 700 cycles at 2 A/g). Furthermore, by using this composite as the anode for HSCs, the HSC shows a high energy density of 156 Wh/kg at 197 W/kg, which also remains at 97 Wh/kg even at a high power density of 8314 W/kg with a stable cycling life, among the best results of the reported HSCs thus far.