Na‐ion capacitors have attracted extensive interest due to the combination of the merits of high energy density of batteries and high power density as well as long cycle life of capacitors. Here, a novel Na‐ion capacitor, utilizing TiO2@CNT@C nanorods as an intercalation‐type anode and biomass‐derived carbon with high surface area as an ion adsorption cathode in an organic electrolyte, is reported. The advanced architecture of TiO2@CNT@C nanorods, prepared by electrospinning method, demonstrates excellent cyclic stability and outstanding rate capability in half cells. The contribution of extrinsic pseudocapacitance affects the rate capability to a large extent, which is identified by kinetics analysis. A key finding is that ion/electron transfer dynamics of TiO2@CNT@C could be effectively enhanced due to the addition of multiwalled carbon nanotubes. Also, the biomass‐derived carbon with high surface area displays high specific capacity and excellent rate capability. Owing to the merits of structures and excellent performances of both anode and cathode materials, the assembled Na‐ion capacitors provide an exceptionally high energy density (81.2 W h kg−1) and high power density (12 400 W kg−1) within 1.0–4.0 V. Meanwhile, the Na‐ion capacitors achieve 85.3% capacity retention after 5000 cycles tested at 1 A g−1.

For developing energy storage devices with both high energy and power density,l ithium-ion hybrid supercapacitors (LIHSs) are the optimal candidate to bridge the gap between lithium-ion batteries (LIBs) and conventional supercapacitors. AL IHS consists of ac apacitor-typec athode and aL IB-typea node.H owever,t he particle size of LIB-type anode materials shouldb ew ithin % 10 nm to overcome the sluggish ion diffusion in the bulk. In addition, capacitor-type cathodem aterials are required to possessh igh capacitance to match with LIB-type anodes. Meanwhile, pre-lithiation provesa ne ffective strategy to achieve high cell voltages and high energy density accordingly.I nt his review we first summarize the requirement on electrode materials for LIHSs, and then propose two levels of LIHSs with the clarification of true LIHSs according to the energy and power density.F inally,w egive an outlook for future LIHSs. SchoolofM aterialsS cience and Engineering NationalInstitute for Advanced MaterialsThe ORCID identification number(s)for the author(s)oft his article can be found under http://dx.

Hierarchical porous structures are highly desired for various applications. However, it is still challenging to obtain such materials with tunable architectures. Here, this paper reports hierarchical nanomaterials with oriented 2D pores by taking advantages of thermally instable bonds in vanadium-based metal-organic frameworks (MOFs). High-temperature calcination of these MOFs accompanied by the loss of coordinated water molecules and other components enables the formation of orderly slit-like 2D pores in vanadium oxide/porous carbon nanorods (VO /PCs). This unique combination leads to an increase of the reactive surface area. In addition, optimized VO /PCs demonstrate high-rate capability and ultralong cycling life for sodium storage. The assembled full cells also show high capacity and cycling stability. This report provides an effective strategy for producing MOFs-derived composites with hierarchical porous architectures for energy storage.

No abstract

No abstract

No abstract