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Hybrid supercapacitors (HSCs) are novel, promising devices having features of both batteries and supercapacitors. Herein, we report HSCs (Li-HSC and Na-HSC in a uniform system) based on an interlayer-expanded MoS2/rGO composite that show ultrahigh energy density and power density as well as superior cycle stability. The 3D network-structured interlayer-expanded MoS2/rGO nanocomposite (3D-IEMoS2@G) was synthesized and employed as the anode. Because the 3D architecture of the graphene skeleton frame delivered sufficient charges and the highly interlayer-expanded MoS2achieved fast ion diffusion, the as-prepared composite exhibited excellent performance as the anode material for both LIBs and SIBs (1600 mAh g−1at 100 mA g−1for the LIB; 580 mAh g−1at 100 mAh g−1and 320 mAh g−1at a high current density of 10 A g−1). When paired with nitrogen-doped hierarchically porous 3D graphene (N-3DG), the obtained Na-HSC surpassed Li-HSC in a uniform system, showing an excellent performance of 140 Wh kg−1at 630 W kg−1, 43 Wh kg−1at an ultrahigh power density of 103 kW kg−1(charge finished within 1.5 s) and no distinct capacity attenuation after over 10000 cycles. Thus, a quantitative kinetic analysis was performed to understand the synergistic effect of the two electrodes and the resulting effect of ions in the hybrid supercapacitors and to further pave a general path for fabricating high-performance HSCs. An energy storage device that combines the advantages of batteries and capacitors has been developed by researchers in China. Batteries store energy electrochemically as charged ions, while supercapacitors store electrical charge electrostatically on a surface. This gives supercapacitors the advantage that they can be charged very quickly, and charged and discharged many times, but they can’t store as much energy as a battery of the same weight. Zheng-Hong Huang from Tsinghua University in Beijing and co-workers created a hybrid device that exhibited both ultra-high energy and power density along with excellent cycle stability. Their structure had an anode made from a composite of interlayer-expanded molybdenum disulfide and graphene oxide. The three-dimensional graphene skeleton supported the electrical charge, while the interlayer-expanded molybdenum disulfide enabled rapid diffusion of ions and provided sufficient energy storage sites. Sodium ion hybrid capacitors is fabricated by interlayer-expanded MoS2/rGO composite and it shows greater performance than lithium ion capacitor.

Lithium-ion capacitors (LICs) are novel advanced electrochemical energy storage (EES) systems integrating both battery and capacitor functions. Most efforts for developing high-power LICs are currently dedicated to nanostructure design of battery-type anodes, which in general results in low packing densities and cannot fundamentally improve the slow Faradaic reaction. Up to now, little attention has been focused on the effects of porous carbon cathodes and the reasonable matching of cathode/anode on the power performance of LICs. Herein, a novel nitrogen-enriched mesoporous carbon nanospheres/graphene (N-GMCS) nanocomposite is demonstrated, which shows simultaneously hierarchical porous structure, 3D conductive network, as well as very high mass density. When such N-GMCS cathode is coupled with prelithiated microcrystalline graphite (PLMG) anode, the integrated device shows quite high packing density which is highly desirable in EES systems. In particular, the PLMG anode in N-GMCS//PLMG system breaks the limitation of slow Faradaic reaction and lithium-ion bulk diffusion, providing an ultrafast capacitor-like electrochemical response. Quite attractive maximum energy density (80Whkg−1, 68.6WhL−1) and state-of-the-art maximum power density (352kWkg−1, 292kWL−1) can be achieved in N-GMCS//PLMG, which are 5 and 2.8 times as large as those of the supercapacitor counterpart, respectively.