Designing and fabricating well-defined heterointerface catalysts with high electrocatalytic performance for oxygen evolution reaction (OER) at the industrial grade current density still remains a huge challenge. Here the flower-like nanosheets with rich Fe2O3/NiFe-layered double hydroxides (LDHs) heterointerfaces were fabricated, and they exhibit superior catalytic activity with a very low overpotential of 220 mV for OER at the industrial grade current density of 500 mA cm− 2 and fast reaction kinetics with a small Tafel slope of 32 mV dec−1. Based on the analyses of operando Raman spectra, DFT theoretical calculations and electrochemical characterizations, the superior electrocatalytic performance of catalysts for OER at the industrial grade current density can be attributed to Fe2O3/NiFe-LDHs heterointerfaces that can obviously promote interfacial electron transfer from Ni2+ to Fe3+ and optimize d-orbit electronic configuration with eg occupancy of Ni close to the unity, resulting in moderate adsorption/desorption energies of oxygenated intermediates, and thus facilitating remarkably electrocatalytic performance and superior intrinsic kinetics for OER in alkaline media. 

Interfacial electronic modulation by Fe2O3/NiFe-LDHs heterostructures for efficient oxygen evolution at high current density

Constructing a Hetero-interface Composed of Oxygen Vacancy-Enriched Co3O4 and Crystalline–Amorphous NiFe-LDH for Oxygen Evolution Reaction

Next-generation batteries based on conversion reactions, including aqueous metal-air batteries, nonaqueous alkali metal-O2 and -CO2 batteries, alkali metal-chalcogen batteries, and alkali metal-ion batteries have attracted great interest. However, their use is restricted by inefficient reversible conversion of active agents. Developing bifunctional catalysts to accelerate the conversion reaction kinetics in both discharge and charge processes is urgently needed. Graphene-, or graphene-like carbon-supported atomically dispersed metal catalysts (G-ADMCs) have been demonstrated to show excellent activity in various electrocatalytic reactions, making them promising candidates. Different from G-ADMCs for catalysis, which only require high activity in one direction, G-ADMCs for rechargeable batteries should provide high activity in both discharging and charging. This review provides guidance for the design and fabrication of bifunctional G-ADMCs for next-generation rechargeable batteries based on conversion reactions. The key challenges that prevent their reversible conversion, the origin of the activity of bifunctional G-ADMCs, and the current design principles of bifunctional G-ADMCs for highly reversible conversion, have been analyzed and highlighted for each conversion-type battery. Finally, a summary and outlook on the development of bifunctional G-ADMC materials for next-generation batteries with a high energy density and excellent energy efficiency are given.

Graphene-Supported Atomically Dispersed Metals as Bifunctional Catalysts for Next-Generation Batteries Based on Conversion Reactions.

Motivating high-valence Nb doping by fast molten salt method for NiFe hydroxides toward efficient oxygen evolution reaction

Recent advances in Ni3S2-based electrocatalysts for oxygen evolution reaction

The exploration of efficient electrocatalysts for energy conversion is important for green energy development. Owing to their high surface areas and unusual electronic structure, 2D electrocatalysts have attracted increasing interest. Among them, non-van der Waals (non-vdW) 2D materials with numerous chemical bonds in all three dimensions and novel chemical and electronic properties beyond those of vdW 2D materials have been studied increasingly over the past decades. Herein, the progress of non-vdW 2D electrocatalysts is critically reviewed, with a special emphasis on electronic structure modulation. Strategies for heteroatom doping, vacancy engineering, pore creation, alloying, and heterostructure engineering are analyzed for tuning electronic structures and achieving intrinsically enhanced electrocatalytic performances. Lastly, a roadmap for the future development of non-vdW 2D electrocatalysts is provided from material, mechanism, and performance viewpoints.

Electronic Modulation of Non-van der Waals 2D Electrocatalysts for Efficient Energy Conversion.

The key bottlenecks preventing the practical application of the lithium–metal anode in the secondary batteries are the uncontrollable growth of dendritic Li and huge volume changes during cycling, which rapidly consume the electrolyte and incur short lifespan and poor electrochemical performance. In general, the use of three-dimensional (3D) porous scaffolds with high lithiophilicity is an effective way to solve these problems. Here, we report on a dendrite-free Li-metal anode enabled by an advanced 3D polypyrrole nanotube sponge (PPy-NS) as a Li host. The pyrrolic nitrogen functional groups guide uniform Li nucleation and growth with low overpotential. The conductive 3D skeleton effectively homogenizes the local electric field and Li-ion flux, further restraining dendrite formation. Benefiting from excellent Li deposition behavior, the 3D PPy-NS delivers a high Coulombic efficiency of 98.7% over 500 cycles and ultralong lifespan (1100 h) together with low overpotential (22 mV at 1 mA cm–²). Moreover, coupled with LiNi₀.₈Co₀.₁Mn₀.₁O₂ cathodes, Li-metal full batteries show a remarkable capacity of 3.0 mA h cm–² with 81.5% of the initial capacity over 140 cycles at discharging rate of 0.5 C under a lean electrolyte of 7 g A h–¹ and negative/positive capacity ratio of 3. This work sheds light on designing and developing advanced 3D lithiophilic hosts for stable dendrite-free Li-metal batteries.

Polypyrrole Nanotube Sponge Host for Stable Lithium-Metal Batteries under Lean Electrolyte Conditions

Electromagnetic interference (EMI) shielding materials have received considerable attention in recent years. The EMI shielding effectiveness (SE) of materials depends on not only their composition but also their microstructures. Among various microstructure prototypes, porous structures provide the advantages of low density and high terahertz wave absorption. In this study, by using carbonised wood (CW) as a template, 1-mm-thick MAX@CW composites (Ti2AlC@CW, V2AlC@CW, and Cr2AlC@CW) with a porous structure were fabricated through the molten salt method. The MAX@CW composites led to the formation of a conductive network and multilayer interface, which resulted in improved EMI SE. The average EMI SE values of the three MAX@CW composites were > 45 dB in the frequency of 0.6–1.6 THz. Among the composites, V2AlC@CW exhibited the highest average EMI SE of 55 dB.

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Yao Li

Papers

Electronic Modulation of Non-van der Waals 2D Electrocatalysts for Efficient Energy Conversion.

Polypyrrole Nanotube Sponge Host for Stable Lithium-Metal Batteries under Lean Electrolyte Conditions

In-situ growth of MAX phase coatings on carbonised wood and their terahertz shielding properties