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.

An ether-based electrolyte was used to reduce polarization and improve the plateau capacity at high rates of loofah sponge-derived hard carbon as the anode material for sodium ion batteries for the first time. The optimization of electrolytes could promote the practical application of hard carbon to sodium ion batteries.

Sodium ion batteries are considered as next-generation energy storage devices; however, stable cathode materials are highly desired and challenging for sodium ion batteries. Herein, we report the preparation of a layered cathode material, P2-Na0.67Co0.5Mn0.5O2, with hierarchical architectures, through a facile and simple sol-gel route. X-ray diffraction (XRD) and high resolution transmission electron microscope elucidated a well-defined P2-type phase structure, and in-situ XRD measurements provided further evidence about the structural stability during desodiation/sodiation. Benefiting from the structural stability, the cathode material delivered a high discharge capacity of 147 mAh g -1 at 0.1 C rate, and excellent cyclic stability with nearly 100% capacity retention over at least 100 cycles at 1 C. More importantly, 88 mAh g -1 was maintained when the electrode was cycled at a very high rate of 30 C, and almost half of its capacity retained over 2000 cycles, which outperform all the reported P2-type cathode materials. With outstanding electrochemical performance and structural flexibility, the P2-Na0.67Co0.5Mn0.5O2 cathode material will promote the practical applications of sodium ion batteries.

Homogeneous ultrasmall T-Nb O nanocrystallites encapsulated in 1D carbon nanofibers (T-Nb O /CNFs) are prepared through electrospinning followed by subsequent pyrolysis treatment. In a Na half-cell configuration, the obtained T-Nb O /CNFs with the merits of unique microstructures and inherent pseudocapacitance, deliver a stable capacity of 150 mAh g at 1 A g over 5000 cycles. Even at an ultrahigh charge-discharge rate of 8 A g , a high reversible capacity of 97 mAh g is still achieved. By means of kinetic analysis, it is demonstrated that the larger ratio of surface Faradaic reactions of Nb O at high rates is the major factor to achieve excellent rate performance. The prolonged cycle durability and excellent rate performance endows T-Nb O /CNFs with potentials as anode materials for sodium-ion batteries.

Oriented SnS nanoflakes were bound on S-doped N-rich carbon nanosheets to increase pseudocapacitance, and this composite delivers high Na-storage capacity and excellent rate capability.

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.

Flake-shaped Na3V2(PO4)3@rGO induced by GO is proposed to improve Na+ and electron transfer of Na3V2(PO4)3 as high-rate and long-life cathodes for sodium-ion batteries.

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