No abstract

Flexible carbon fiber cloth (CFC) is an important scaffold and/or current collector for active materials in the development of flexible self-supportive electrode materials (SSEMs), especially in lithium-ion batteries. However, during the intercalation of Li ions into the matrix of CFC (below 0.5 V vs. Li/ Li + ), the incompatibility in the capacity of the CFC, when used directly as an

Interfacial engineering and elemental doping are the two parameters to enhance the catalytic behavior of cobalt nitrides for the alkaline hydrogen evolution reaction (HER). However, simultaneously combining these two parameters to improve the HER catalytic properties of cobalt nitrides in alkaline media is rarely reported and also remains challenging in acidic media. Herein, it is demonstrated that high‐valence non‐3d metal and non‐metal integration can simultaneously achieve Co‐based nitride/oxide interstitial compound phase boundaries on stainless steel mesh (denoted Mo‐Co5.47N/N‐CoO) for efficient HER in alkaline and acidic media. Density functional theory (DFT) calculations show that the unique structure does not only realize multi‐active sites, enhanced water dissociation kinetics, and low hydrogen adsorption free energy in alkaline media, but also enhances the positive charge density of hydrogen ions (H+) to effectively allow H+ to receive electrons from the catalysts surface toward promoting the HER in acidic media. As a result, the as‐prepared Mo‐Co5.47N/N‐CoO demands HER overpotential of −28 mV@10 mA cm−2 in an alkaline medium, and superior to the commercial Pt/C at a current density > 44 mA cm−2 in acidic medium. This work paves a useful strategy to design efficient cobalt‐based electrocatalysts for HER and beyond.

No abstract

The electric‐field effect is an important factor to enhance the charge diffusion and transfer kinetics of interfacial electrode materials. Herein, by designing a heterojunction, the influence of the electric‐field effect on the kinetics of the MoS2 as cathode materials for aqueous Zn‐ion batteries (AZIBs) is deeply investigated. The hybrid heterojunction is developed by hydrothermal growth of MoS2 nanosheets on robust titanium‐based transition metal compound ([titanium nitride, TiN] and [titanium oxide, TiO2]) nanowires, denoted TNC@MoS2 and TOC@MoS2 NWS, respectively. Benefiting from the heterostructure architecture and electric‐field effect, the TNC@MoS2 electrodes exhibit an impressive rate performance of 200 mAh g−1 at 50 mA g−1 and cycling stability over 3000 cycles. Theoretical studies reveal that the hybrid architecture exhibits a large‐scale electric‐field effect at the interface between TiN and MoS2, enhances the adsorption energy of Zn‐ions, and increases their charge transfer, which leads to accelerated diffusion kinetics. In addition, the electric‐field effect can also be effectively applied to TiO2 and MoS2, confirming that the concept of heterostructures stimulating electric‐field can provide a relevant understanding for the architecture of other cathode materials for AZIBs and beyond.