The plating/stripping of Li dendrites can fracture the static solid electrolyte interphase (SEI) and cause significant dynamic volume variations in the Li anode, which give rise to poor cyclability ...and severe safety hazards. Herein, a tough polymer with a slide‐ring structure was designed as a self‐adaptive interfacial layer for Li anodes. The slide‐ring polymer with a dynamically crosslinked network moves freely while maintaining its toughness and fracture resistance, which allows it can to dissipate the tension induced by Li dendrites on the interphase layer. Moreover, the slide‐ring polymer is highly stretchable, elastic, and displays an ultrafast self‐healing ability, which allows even pulverized Li to remain coalesced without disintegrating upon consecutive cycling. The Li anodes demonstrate greatly improved suppression of Li dendrite formation, as evidenced by the high critical current density (6 mA cm−2) and stable cycling for the full cells with high‐areal capacity LiFePO4, high‐voltage NCM, and S cathodes.
A slide‐ring polymer with a high stiffness, high toughness and excellent fracture resistance is designed to adapt its shape to dynamic electrode volume variations and stabilize the lithium anode upon cycling.
The development of bifunctional electrocatalysts with high performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with earth-abundant elements is still a challenge ...in electrochemical water splitting technology. Herein, we fabricated a free-standing electrocatalyst in the form of vertically oriented Fe-doped Ni3S2 nanosheet array grown on three-dimensional (3D) Ni foam (Fe-Ni3S2/NF), which presented a high activity and durability for both HER and OER in alkaline media. On the basis of systematic experiments and calculation, the Fe-doping was evidenced to increase the electrochemical surface area, improve the water adsorption ability, and optimize the hydrogen adsorption energy of Ni3S2, which resulted in the enhancement of HER activity on Fe-Ni3S2/NF. Moreover, metal sites of Fe-Ni3S2/NF were proved to play a significant role in the HER process. During the catalysis of OER, the formation of Ni–Fe (oxy)hydroxide was observed on the near-surface section of Fe-Ni3S2/NF, and the introduction of the Fe element dramatically enhanced the OER activity of Ni3S2. The overall water splitting electrolyzer assembled by Fe-Ni3S2/NF exhibited a low cell voltage (1.54 V @ 10 mA cm–2) and a high durability in 1 M KOH. This work demonstrated a promising bifunctional electrocatalyst for water electrolysis in alkaline media with potential application in the future.
The uncontrolled growth of Li dendrites upon cycling might result in low coulombic efficiency and severe safety hazards. Herein, a lithiophilic binary lithium–aluminum alloy layer, which was ...generated through an in situ electrochemical process, was utilized to guide the uniform metallic Li nucleation and growth, free from the formation of dendrites. Moreover, the formed LiAl alloy layer can function as a Li reservoir to compensate the irreversible Li loss, enabling long‐term stability. The protected Li electrode shows superior cycling over 1700 h in a Li|Li symmetric cell.
Dendrite‐free anodes: An efficient lithium–aluminum alloy medium with increased affinity for Li and generated through an in situ electrochemical process is engineered to guide uniform Li nucleation and suppress the growth of Li dendrites.
A mechanically robust, ultraelastic foam with controlled multiscale architectures and tunable mechanical/conductive performance is fabricated via 3D printing. Hierarchical porosity, including both ...macro‐ and microscaled pores, are produced by the combination of direct ink writing (DIW), acid etching, and phase inversion. The thixotropic inks in DIW are formulated by a simple one‐pot process to disperse duo nanoparticles (nanoclay and silica nanoparticles) in a polyurethane suspension. The resulting lightweight foam exhibits tailorable mechanical strength, unprecedented elasticity (standing over 1000 compression cycles), and remarkable robustness (rapidly and fully recover after a load more than 20 000 times of its own weight). Surface coating of carbon nanotubes yields a conductive elastic foam that can be used as piezoresistivity sensor with high sensitivity. For the first time, this strategy achieves 3D printing of elastic foam with controlled multilevel 3D structures and mechanical/conductive properties. Moreover, the facile ink preparation method can be utilized to fabricate foams of various materials with desirable performance via 3D printing.
Mechanically robust hierarchical foam with unprecedented elasticity, controllable structure, and performance is fabricated by 3D printing using concentrated nanofiller‐based inks. Combination of direct ink writing, acid etching, and phase inversion produces pores in three different length scale, which are tunable through ink formulation or computer‐designed geometries. Surface coating of carbon nanotubes yields a highly sensitive stress sensor with excellent recoverability.
Silicon has attracted much attention as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and rich resource abundance. However, the practical battery ...use of Si is challenged by its low conductivity and drastic volume variation during the Li uptake/release process. Tremendous efforts have been made on shrinking the particle size of Si into nanoscale so that the volume variation could be accommodated. However, the bare nano-Si material would still pulverize upon (de)lithiation. Moreover, it shows an excessive surface area to invite unlimited growth of solid electrolyte interface that hinders the transportation of charge carriers, and an increased interparticle resistance. As a result, the Si nanoparticles gradually lose their electrical contact during the cycling process, which accounts for poor thermodynamic stability and sluggish kinetics of the anode reaction versus Li. To address these problems and improve the Li storage performance of nano-Si anode, proper structural design should be applied on the Si anode. In this perspective, we will briefly review some strategies for improving the electrochemistry versus Li of nano-Si materials and their derivatives, and show opinions on the optimal design of nanostructured Si anode for advanced LIBs.
The growth of white‐rot fungi is related to the superior infiltrability and biodegradability of hyphae on a lignocellulosic substrate. The superior biodegradability of fungi toward plant substrates ...affords tailored microstructures, which benefits subsequently high efficient carbonization and chemical activation. Here, the mechanism underlying the direct growth of mushrooms toward the lignocellulosic substrate is elucidated and a fungi‐enabled method for the preparation of porous carbons with ultrahigh specific surface area (3439 m2 g−1) is developed. Such porous carbons could have potential applications in energy storage, environment treatment, and electrocatalysis. The present study reveals a novel pore formation mechanism in root‐colonizing fungi and anticipates a valuable function for fungi in developing the useful porous carbons with a high specific surface area.
A universal fungi‐enabled method for the preparation of porous carbons with ultrahigh specific surface area for energy storage, adsorption, and electrocatalysis is developed. Hyphae infiltrate into the plant cell wall to secrete corresponding exoenzymes to generate a multidimensional framework, which is beneficial to the following carbonization and activation process.
The paper treats an agent-based model with averaging dynamics to which we refer as the
K
-
averaging model
. Broadly speaking, our model can be added to the growing list of dynamics exhibiting ...self-organization such as the well-known Vicsek-type models (Aldana et al. in: Phys Rev Lett 98(9):095702, 2007; Aldana and Huepe in: J Stat Phys 112(1–2):135–153, 2003; Pimentel in: Phys. Rev. E 77(6):061138, 2008). In the
K
-averaging model, each of the
N
particles updates their position by averaging over
K
randomly selected particles with additional noise. To make the
K
-averaging dynamics more tractable, we first establish a propagation of chaos type result in the limit of infinite particle number (i.e.
N
→
∞
) using a martingale technique. Then, we prove the convergence of the limit equation toward a suitable Gaussian distribution in the sense of Wasserstein distance as well as relative entropy. We provide additional numerical simulations to illustrate both results.
It is a great challenge to fabricate electrode with simultaneous high activity for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Herein, a high‐performance ...bifunctional electrode formed by vertically depositing a porous nanoplate array on the surface of nickel foam is provided, where the nanoplate is made up by the interconnection of trinary Ni–Fe–Mo suboxides and Ni nanoparticles. The amorphous Ni–Fe–Mo suboxide and its in situ transformed amorphous Ni–Fe–Mo (oxy)hydroxide acts as the main active species for HER and OER, respectively. The conductive network built by Ni nanoparticles provides rapid electron transfer to active sites. Moreover, the hydrophilic and aerophobic electrode surface together with the hierarchical pore structure facilitate mass transfer. The corresponding water electrolyzer demonstrates low cell voltage (1.50 V @ 10 mA cm−2 and 1.63 V @ 100 mA cm−2) with high durability at 500 mA cm−2 for at least 100 h in 1 m KOH.
A high‐performance bifunctional electrode in the form of a porous nanoplate array vertically aligned on nickel foam for overall water splitting is provided. The porous nanoplate is built by the interconnection of trinary Ni–Fe–Mo suboxides and Ni nanoparticles, which is featured with amorphous active material and rapid electron/mass transfer.
Indium-oxide (In2O3) nanobelts coated by a 5-nm-thick carbon layer provide an enhanced photocatalytic reduction of CO2 to CO and CH4, yielding CO and CH4 evolution rates of 126.6 and 27.9 μmol h–1, ...respectively, with water as reductant and Pt as co-catalyst. The carbon coat promotes the absorption of visible light, improves the separation of photoinduced electron–hole pairs, increases the chemisorption of CO2, makes more protons from water splitting participate in CO2 reduction, and thereby facilitates the photocatalytic reduction of CO2 to CO and CH4.
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