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Enhancement of supercapacitors (SCs) with high-energy density and high-power density is still a great challenge. In this paper, a facile strategy for in situ anchoring of Co3O4 particles on N doped carbon cloth (pCoNCC) is reported. Due to the interaction of the doped N and Co3O4, the electrochemical performance improves significantly, reaching 1,940.13 mF·cm−2 at 1 mA·cm−2 and energy density of 172.46 µWh·cm−2 at the power density of 400 µW·cm−2, much larger than that without N doping electrode of 28.5 mF·cm−2. An aqueous symmetric supercapacitor (ASSC) assembled by two pCoNCC electrodes achieves a maximum energy density of 447.42 µWh·cm−2 and a highest power density of 8,000 µW·cm−2. Utilizing such a high-energy storage ASSC, a digital watch and a temperature-humidity detector are powered for nearly 1 and 2 h, respectively. Moreover, the ASSC displays a superb electrochemical stability of 87.7% retention after 10,000 cycles at 40 mA·cm−2. This work would provide a new sight to enhance active materials performance and be beneficial for the future energy storage and supply systems. [ABSTRACT FROM AUTHOR]

A new vertically aligned nanocomposite (VAN) structure based on two-dimensional (2D) layered oxides has been designed and self-assembled on both LaAlO3 (001) and SrTiO3 (001) substrates. The new VAN structure consists of epitaxially grown Co3O4 nanopillars embedded in the Bi2WO6 matrix with a unique 2D layered structure, as evidenced by the microstructural analysis. Physical property measurements show that the new Bi2WO6-Co3O4 VAN structure exhibits strong ferromagnetic and piezoelectric response at room temperature as well as anisotropic permittivity response. This work demonstrates a new approach in processing multifunctional VANs structure based on the layered oxide systems towards future nonlinear optics, ferromagnets, and multiferroics. [ABSTRACT FROM AUTHOR]