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CuCo2O4 nanoparticles have been synthesized by a simple and low-cost urea combustion method and characterized as bifunctional catalysts for non-aqueous Li-air batteries. The resulting CuCo2O4 catalyst has been demonstrated to effectively reduce the charge-discharge polarization of Li-air batteries in a simulated air environment (80% Ar : 20% O2).

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time-consuming, entailing hazardous chemicals or harsh fabrication conditions, and not universal for large-scale application. [4] For example, Hu and co-workers used phosphomolybdic acid (PMo) to initiate the polymerization of polypyrrole for 12 h, which was then subjected to an annealing process to finally obtain the pomegranatelike N, P-doped Mo 2 C@C nanospheres. [3g] The poisonous nature of the pyrrole monomer reactant and the prolonged polymerization process limits practical applications of this method. Besides, ions exchange resin was used to absorb the molybdenum source for more than 20 h, and the composite was then annealed to give rise to Mo 2 C nanoparticles wrapped in the carbon matrix. [5] The adsorptive process is really time-consuming and the utilization of the molybdenum salts is extremely low. As a result, it remains a great challenge to directly and controllably synthesize highly efficient TMC-based electrodes for lithium-ion batteries.Moreover, in view of large volume change of TMCs during the repeating lithiation/delithiation process, porous structure with sufficient void space had been considered as an effective path to mitigate the strike of volume expansion. Previous reports show that interconnected porous nanosheets, arranging into highly separated and permeable porous networks, have Layered stacking and highly porous N, P co-doped Mo 2 C/C nanosheets are prepared from a stable Mo-enhanced hydrogel. The hydrogel is formed through the ultrafast cross-linking of phosphomolybdic acid and chitosan. During the reduction of the composite hydrogel framework under inert gas protection, highly porous N and P co-doped carbon nanosheets are produced with the in situ formation of ultrafine Mo 2 C nanoparticles highly distributed throughout the nanosheets which are entangled via a hierarchical lamellar infrastructure. This unique architecture of the N, P co-doped Mo 2 C/C nanosheets tremendously promote the electrochemical activity and operate stability with high specific capacity and extremely stable cycling. In particular, this versatile synthetic strategy can also be extended to other polyoxometalate (such as phosphotungstic acid) to provide greater opportunities for the controlled fabrication of novel hierarchical nanostructures for next-generation high performance energy storage applications.

Si-based nanostructure composites have been intensively investigated as anode materials for next-generation lithium-ion batteries because of their ultra-high-energy storage capacity. However, it is still a great challenge to fabricate a perfect structure satisfying all the requirements of good electrical conductivity, robust matrix for buffering large volume expansion, and intact linkage of Si particles upon long-term cycling. Here, we report a novel design of Si-based multicomponent three-dimensional (3D) networks in which the Si core is capped with phytic acid shell layers through a facile high-energy ball-milling method. By mixing the functional Si with graphene oxide and functionalized carbon nanotube, we successfully obtained a homogeneous and conductive rigid silicon-based gel through complexation. Interestingly, this Si-based gel with a fancy 3D cross-linking structure could be writable and printable. In particular, this Si-based gel composite delivers a moderate specific capacity of 2711 mA h g at a current density of 420 mA g and retained a competitive discharge capacity of more than 800.00 mA h g at the current density of 420 mA g after 700 cycles. We provide a new method to fabricate durable Si-based anode material for next-generation high-performance lithium-ion batteries.

Hydrogen energy is critical for achieving carbon neutrality. Heterostructured materials with single metal-atom dispersion are desirable for hydrogen production. However, it remains a great challenge to achieve large-scale fabrication of single atom-anchored heterostructured catalysts with high stability, low cost, and convenience. Here, we report single iron (Fe) atom-dispersed heterostructured Mo-based nanosheets developed from a mineral hydrogel. These rationally designed nanosheets exhibit excellent hydrogen evolution reaction (HER) activity and reliability in alkaline condition, manifesting an overpotential of 38.5 mV at 10 mA cm−2, and superior stability without performance deterioration over 600 h at current density up to 200 mA cm−2, superior to most previously reported non-noble-metal electrocatalysts. The experimental and density functional theory results reveal that the O-coordinated single Fe atom-dispersed heterostructures greatly facilitated H2O adsorption and enabled effective adsorbed hydrogen (H*) adsorption/desorption. The green, scalable production of single-atom-dispersed heterostructured HER electrocatalysts reported here is of great significance in promoting their large-scale implementation.

In this work, UiO-66-based metal−organic frameworks are investigated as an oxygen reduction reaction (ORR) catalyst for the first time. UiO-66-NO 2 is solvothermally grown on the surface of cobalt phthalocyanine-anchored carbon nanotube (CoCNT) surface, serving as an oxygen "pump" to accelerate the oxygen reduction reaction (ORR). The UiO-66-NO 2 -attached CoCNT (UiO-66-NO 2 @CoCNT) exhibits superior electrochemical catalytic properties, exceeding the state-of-the-art commercial 20% Pt/C catalyst with more positive half-wave potential (15 mV difference, at 1600 rpm), better stability (no significant degradation for UiO-66-NO 2 @ CoCNT vs 19% degradation for 20% Pt/C after 25 000 s), and higher methanol tolerance. When assembled in a flexible zinc−air battery, the UiO-66-NO 2 @CoCNT remains a competitive alternative to commercial 20% Pt/ C catalyst with comparable power density and excellent flexibility, suggesting its potential in wearable electronic devices. The outstanding performance of UiO-66-NO 2 @CoCNT composite is closely related to the synergetic effect among the three components: CNT as a conductive backbone, cobalt phthalocyanines as the oxygen reduction catalytic active site, and UiO-66-NO 2 as an ideal oxygen adsorption pump (the oxygen diffusion rate is 4.8 times that of 20% Pt/C and 17.7 times that of CoCNT). The synergy between the three components facilitates oxygen adsorption, transfer of adsorbed oxygen molecules, oxygen reduction, and electron conduction.

Greatly reinforced synergistic effect between in situ precipitated Fe3O4 and NSCNTs contribute to extraordinary ORR performance comparable to that of commercial Pt/C.