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 this study, success was achieved in preparing a highly ordered two-dimensional (2D) carbon/TiO2 (C/TiO2) nanosheet composite using commercially available organic molecules with multifunctional groups and taking advantage of the wedge effects, oxidative polymerization, and carbonization. An experiment was conducted to validate the excellent performance of this 2D composite with respect to interfacial energy storage. The coin cell with 2D C/TiO2 nanosheet composite demonstrates a specific capacity of as high as 510 mAh g–1 and a high specific energy of 390.9 Wh kg–1 at a specific power of 75.9 W kg–1 with a current density of 0.1 A g–1, and it also remains 39.0 Wh kg–1 at a specific power of 8.2 kW kg–1 with a high current density of 12.8 A g–1. The excellent electrochemical performance can be attributed to the superior artificial interface capacitive Li+ storage capability, which would bridge the energy and power density gap between batteries and capacitors. Meanwhile, there are two varieties of carbon derivatives, 2D carbon nanosheet stacks and exfoliated carbon nanosheets, which can be obtained by wet-chemical etching and mechanical peeling. The experimental route is simple from commercially available raw materials, and it could be scalable at a low cost and large scale, which makes it suitable for application in various fields such as energy storage, nanocatalysis, sensors, and so on.

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 materials in an alternating sequence is a great challenge in synthesis. Herein, we report a novel strategy to construct TiO 2 nanosheets into 2D pillar-layer architectures by employing benzidine molecular assembly as pillars. Then, 2D carbon/TiO 2 nanosheet composite with a periodic interlayer distance of 1.1 nm was obtained following a polymerization and carbonization process. This method not only alleviates the strain arising from the torsion of binding during carbonization but also hinders the structural collapse of TiO 2 due to the intercalation of the carbon layer by rational control of annealing conditions. The composite material possesses a large carbon/TiO 2 interface, providing abundant active sites for ultrafast pseudocapacitive charge storage, thus displaying a superior high-rate performance with a specific capacity of 67.8 mAh g −1 at a current density of 12.8 A g −1 based on the total electrode and excellent cyclability with 87.4% capacity retention after 3000 cycles.