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Graphene-doped flower-like cobalt–nickel–tungsten–boron oxides with self-oxidation were used as high-performance supercapacitor electrode materials.

Shape-stabilized phase-change composites (SSPCCs) have been widely applied for thermal energy storage and thermal management because of their excellent properties. To further improve their thermal conductivity and thermal cycling stability, we successfully designed and synthesized a series of SSPCCs with three-dimensional (3D) thermally conductive networks by exploiting the synergistic effect between one-dimensional (1D) carbon nanotubes (CNTs) and two-dimensional (2D) hexagonal boron nitride (h-BN). The interconnected thermally conductive network composed of h-BN and multiwalled carbon nanotubes (MWCNTs) enhanced the SSPCC performance. The micromorphologies of the prepared SSPCCs revealed that well-dispersed MWCNTs, hydroxylated h-BN, and polyethylene glycol (PEG) molecular chains effectively bonded into a 3D cross-linking structure of the SSPCCs. Moreover, the chemical and crystalline structural and thermal properties and thermal cycling stability of the novel SSPCCs were systematically investigated by various characterization techniques. The presence of a 3D thermally conductive network in the as-synthesized SSPCCs evidently improved the shape stability, phase-change behavior, and thermal stability. Benefiting from the 3D nanostructural uniqueness of SSPCCs, the thermal conductivity of SSPCC-2 was up to 1.15 W m–1 K–1, which represented a significant enhancement of 239.7% compared with that of pure PEG. Meanwhile, the efficient synergistic effect of h-BN and MWCNTs remarkably enhanced the heat-transfer rate of the SSPCCs. These results demonstrate that the prepared SSPCCs have potential for applications in thermal energy storage and thermal management systems. This study opens a new avenue toward the development of SSPCCs with good comprehensive properties.

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Using egg white as raw material, the activated carbon materials with nitrogen doping were synthesized by a two‐step method involving carbonization and activation. Structure characterization showed this porous carbon had a three‐dimensional honeycomb structure composed of interconnected micropores and mesopores, which resulted in a high specific surface area of 2918 m2 g−1. Due to KOH activation, the appropriate ratio of micropore to mesopore could optimize the diffusion channel of electrolyte ion and increase the contact area between electrolyte and electrode. Thus the egg white‐derived porous carbon (EWC) showed outstanding electrochemical properties as supercapacitor electrode. In three‐electrode system, a high specific capacitance of 335 F g−1 could be achieved at a current density of 0.5 A g−1, and only 8.3% of capacitance was lost after 10000 cycles. For the symmetrical supercapacitor fabricated with as‐prepared carbon material, it exhibited a specific capacitance of 68 F g−1 and a maximum energy density of 13.6 W h kg−1.