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Highly ordered, hierarchically porous and interlinked carbon nanosheet stacks are explored via an intercalation reaction into the layered TiO2 template. Herein, benzidine is used as the raw materia...

Interfacial energy storage contributes a new mechanism to the emergence of energy storage devices with not only a high-energy density of batteries but also a high-power density of capacitors. In th...

Intercalation of carbon nanosheets into two-dimensional (2D) inorganic materials could enhance their properties in terms of mechanics and electrochemistry, but sandwiching these two kinds of materi...

A novel insertable and pseudocapacitive Li+ ion material for highly ordered layered montmorillonite/carbon is explored in the present study. The commercially available protonated montmorillonite and 3,3′-diaminobenzidine act as starting materials to synthesize the layered material via hydrothermal intercalation, oxidative polymerization and carbonization. This method of preparing montmorillonite/carbon nanocomposite exhibits several advantages. To be specific, raw materials are low cost and naturally abundant; the montmorillonite can undergo proton exchange easily to form a permutable proton-type material, and the protons in the layered nanocomposite can be directly substituted by the polymerizable molecules (e.g., 3,3′-diaminobenzidine). Accordingly, a sheet-like montmorillonite/carbon layered nanocomposite is achieved with the carbon stacking on the montmorillonite substrate for the intercalation behavior. As revealed from the electrochemical results, montmorillonite/carbon nanocomposite can deliver a high reversible capacity of 1432 mA h g−1 at 50 mA g−1 and superior rate capacity of 920 mA h g−1 at 10 000 mA g−1 for the lithium ion battery. Furthermore, the full cell with LiFePO4 as cathode and montmorillonite/carbon as anode maintains 94% capacity retention over 50 cycles as well as high coulombic efficiency.

Nitrogen doped porous carbons are the most attractive electrode materials for supercapacitors due to their large surface area and surface pseudocapacitance. Herein, a nitrogen-doped porous carbon with an ultra-high specific surface area of 3709 m2 g−1 is synthesized by a simple one-pot polymerization and calcination process. The porous carbon exhibits both high specific capacitance and excellent rate capability in a wide pH range. High specific capacitances of 304.3, 348.0, 185.4 and 298.0 F g−1 are achieved for the nitrogen-doped porous carbon in 1 M H2SO4, 6 M KOH, 21 m LiTFSI and 1 M Li2SO4 at 2 mV s−1, respectively. The symmetrical supercapacitor with this porous carbon as the electrodes can deliver a high energy density of 25.9 Wh kg−1 at a power density of 339.6 W kg−1 with an operating cell voltage of 1.7 V in 1 M Li2SO4 electrolyte, and a good cycle stability with 84% of its initial specific capacitance remains after 23,000 cycles. The superior electrochemical properties can be attributed to the large specific surface area, well-defined hierarchical pores, and high level of disorder structure for the N-doped carbon material.

Poor rate capability and cyclability are the major barriers to using TiO2 as the next generation anode material for high-performance lithium-ion batteries. In this study, a sandwich-like composite consisting of atomically defined two-dimensional (2D) carbon nanosheet is constructed by the confined synthesis in the galleries of layered TiO2 nanosheet with the superior cycling and rate performances as the anode material for lithium-ion batteries. It is first experimentally revealed that the interfacial charge storage between unilamellar TiO2 nanosheet and carbon nanosheet in the Carbon/TiO2 nanosheet stack and the excellent structure stability during the discharge/charge process contribute to the superior performance of the composites. The resultant composite exhibits a high specific capacity (568 mAh g−1) with a specific energy of 407.4 Wh kg−1 at a specific power of 71.7 W kg−1, and remains 88.0 Wh kg−1 at a specific power of 9.0 kW kg−1. Apart from promising lithium-ion battery anode, this 2D Carbon/TiO2 composite also has immense potential for applications in other areas such as sodium/potassium-ion batteries, supercapacitor, and catalysis.