Regulating "Tip Effect" and Zn2+-Deposition Kinetics by In Situ Constructing Interphase for Low Voltage Hysteresis and Dendrite-Free Zn Anode.

Metal zinc (Zn) is being explored as a possible anode for aqueous zinc ion batteries (AZIBs). However, unrestrained Zn dendrite caused by "tip effect" and chemical corrosion continue to plague the Zn deposition process, limiting the functionality of AZIBs and prohibiting their use at high current densities. This work presents an in situ approach for introducing homogeneous ZnO nanoarrays onto the surface of Zn foil (Zn@ZnO NAs) as a functional protective interphase. On the one hand, well-distributed ZnO NAs protection layer can regulate the "tip effect" and confine the growth of Zn dendrite. On the other hand, the ZnO NAs layer can enhance the desolvation and diffusion process of Zn2+ on the surface of anode, attributing to low voltage hysteresis and exceptional electrochemical performance at high current densities. As a result, the Zn@ZnO NAs exhibits a low voltage hysteresis of 50.8 mV with a superb lifespan of 1200 h at a current density of 5 mA cm-2. Moreover, Zn@ZnO NAs||α-MnO2 full-cell shows a superior cycling performance after 500 cycles at 0.5 A g-1 with a capacity of 216.69 mAh g-1. This work is expected to provide ideas for designing other reversible zinc anode chemical systems, especially under a high current density.

Constructing a Size-Controllable Spherical P2-Type Layered Oxides Cathode That Achieves Practicable Sodium-Ion Batteries.

P2-type layered metal oxides are regarded as promising cathode materials for sodium-ion batteries due to their high voltage platform and rapid Na+ diffusion kinetics. However, limited capacity and unfavorable cycling stability resulting from inevitable phase transformation and detrimental structure collapse hinder their future application. Herein, based on P2-type Na0.67Ni0.18Mn0.67Cu0.1Zn0.05O2, we synthesized a series of secondary spherical morphology cathodes with different radii derived from controlling precursors prepared by a coprecipitation method, which can be promoted to large-scale production. Consequently, the synthesized materials possessed a high tap density of 1.52 g cm-3 and a compacted density of 3.2 g cm-3. The half cells exhibited a specific capacity of 111.8 mAh g-1 at a current density of 0.1 C as well as an 82.64% capacity retention with a high initial capacity of 85.80 mAh g-1 after 1000 cycles under a rate of 5 C. Notably, in situ X-ray diffraction revealed a reversible P2-OP4 phase transition and displayed a tiny volume change of 6.96% during the charge/discharge process, indicating an outstanding cycling stability of the modified cathode. Commendably, the cylindrical cell achieved a capacity of 4.7 Ah with almost no change during 1000 cycles at 2 C, suggesting excellent potential for future applications.

Constructing Ru-O-TM Bridge in NiFe-LDH Enables High Current Hydrazine-assisted H2 Production.

Hydrazine oxidation-assisted water splitting is a critical technology to tackle the high energy consumption in large-scale H2 production. Ru-based electrocatalysts hold promise for synergetic hydrogen reduction (HER) and hydrazine oxidation (HzOR) catalysis but are hindered by excessive superficial adsorption of reactant intermediate. Herein, this work designs Ru cluster anchoring on NiFe-LDH (denoted as Ruc/NiFe-LDH), which effectively enhances the intermediate adsorption capacity of Ru by constructing Ru─O─Ni/Fe bridges. Notably, it achieves an industrial current density of 1 A cm-2 at an unprecedentedly low voltage of 0.43 V, saving 3.94 kWh m-3 H2 in energy, and exhibits remarkable stability over 120 h at a high current density of 5 A cm-2. Advanced characterizations and theoretical calculation reveal that the presence of Ru─O─Ni/Fe bridges widens the d-band width (Wd) of the Ru cluster, leading to a lower d-band center and higher electron occupation on antibonding orbitals, thereby facilitating moderate adsorption energy and enhanced catalytic activity of Ru.

Employing Graph Neural Networks for Predicting Electrode Average Voltages and Screening High-Voltage Sodium Cathode Materials.

For many years, humans have been relentlessly focused on enhancing battery longevity and boosting energy storage capacities. The performance and durability of a battery depend significantly on the material used for its electrodes. In this context, merging machine learning with density functional theory (DFT) calculations has emerged as a pivotal approach to advancing the exploration of battery crystal structures. We present a new method that combines a graph convolutional neural network (GNN) with a Transformer convolutional layer, which we call Transformer-GNN. To underscore its efficacy, we benchmarked Transformer-GNN against three established statistical machine learning models: Support Vector Machine, Random Forest, and XGBoost. We also developed a standard GNN, which we refer to as Basic-GNN. Additionally, we compared Basic-GNN with Transformer-GNN to highlight the improvements brought about by incorporating the Transformer convolutional layer. The Transformer-GNN model outperforms the other models, achieving the highest R2 value of 0.82 and the lowest mean squared error of 0.3161. Our findings demonstrate that the Transformer-GNN can profoundly understand battery crystal structures, thus forging the path toward more sophisticated and durable battery systems. Leveraging the GNN model's voltage predictions in tandem with the capacity data sourced from the database, we screened and pinpointed Na(NiO2)2 as a high-voltage (higher than 5 V), high-capacity sodium cathode material. We conducted DFT calculations on Na(NiO2)2 and revealed the migration mechanism of the Na ions.

Precise regulation of phosphorus in nitrogen-coordinated porous carbon spheres for tunable CO2 electroreduction to syngas.

The production of high-demand syngas with tunable ratios by CO2 electroreduction has attracted considerable research interest. However, it is challenging to balance the evolution performance of H2 and CO with wide H2/CO ratios, while maintaining high efficiency. Herein, nitrogen-coordinated hierarchical porous carbon spheres with varying phosphorus content (PxNC-T) are assembled to regulate syngas production performance. The precise introduction of P modulates the local charge distribution of nitrogen-coordinated carbons, thereby accelerating the protonation process of ∗CO2-to-∗COOH and promoting moderate H∗ adsorption. Specifically, syngas with wide H2/CO ratios (0.60-4.98) is obtained over a low potential range (-0.46 to -0.86 V vs. RHE). As a representative, P1.0NC-900 presents a remarkable current density (-152 mA cm-2) at -1.0 V vs. RHE in flow cells and delivers a decent peak power density (1.93 mW cm-2) in reversible Zn-CO2 batteries. Our work provides valuable insights into the rational design of carbon-based catalysts for CO2 reduction.

Defect-induced triple synergistic modulation in copper for superior electrochemical ammonia production across broad nitrate concentrations.

Nitrate can be electrochemically degraded to produce ammonia while treating sewage while it remains grand challenge to simultaneously realize high Faradaic efficiency and production rate over wide-range concentrations in real wastewater. Herein, we report the defect-rich Cu nanowire array electrode generated by in-situ electrochemical reduction, exhibiting superior performance in the electrochemical nitrate reduction reaction benefitting from the triple synergistic modulation. Notably, the defect-rich Cu nanowire array electrode delivers current density ranging from 50 to 1100 mA cm-2 across wide nitrate concentrations (1-100 mM) with Faradaic efficiency over 90%. Operando Synchrotron radiation Fourier Transform Infrared Spectroscopy and theoretical calculations revealed that the defective Cu sites can simultaneously enhance nitrate adsorption, promote water dissociation and suppress hydrogen evolution. A two-electrode system integrating nitrate reduction reaction in industrial wastewater with glycerol oxidation reaction achieves current density of 550 mA cm-2 at -1.4 V with 99.9% ammonia selectivity and 99.9% nitrate conversion with 100 h stability, demonstrating outstanding practicability.

Recent Advancements in Electrochemical Hydrogen Production via Hybrid Water Splitting.

As one of the most promising approaches to producing high-purity hydrogen (H2 ), electrochemical water splitting powered by the renewable energy sources such as solar, wind, and hydroelectric power has attracted considerable interest over the past decade. However, the water electrolysis process is seriously hampered by the sluggish electrode reaction kinetics, especially the four-electron oxygen evolution reaction at the anode side, which induces a high reaction overpotential. Currently, the emerging hybrid electrochemical water splitting strategy is proposed by integrating thermodynamically favorable electro-oxidation reactions with hydrogen evolution reaction at the cathode, providing a new opportunity for energy-efficient H2 production. To achieve highly efficient and cost-effective hybrid water splitting toward large-scale practical H2 production, much work has been continuously done to exploit the alternative anodic oxidation reactions and cutting-edge electrocatalysts. This review will focus on recent developments on electrochemical H2 production coupled with alternative oxidation reactions, including the choice of anodic substrates, the investigation on electrocatalytic materials, and the deep understanding of the underlying reaction mechanisms. Finally, some insights into the scientific challenges now standing in the way of future advancement of the hybrid water electrolysis technique are shared, in the hope of inspiring further innovative efforts in this rapidly growing field.

Construction of Asymmetrical Dual Jahn-Teller Sites for Photocatalytic CO2 Reduction.

Photocatalytic CO2 reduction (PCR) expresses great attraction to convert useless greenhouse gas into valuable chemical feedstock. However, the weak interactions between catalytic sites and PCR intermediates constrains the PCR activity and selectivity. Herein, we proposed a new strategy to match the intermediates due to the maximum orbital overlap of catalytic sites and C1 intermediates by establishing dual Jahn-Teller (J-T) sites, in which, the strongly asymmetric J-T sites can break the nonpolar CO2 molecules and self-adapt the different structure of C1 intermediates. Taking cobalt carbonate hydroxide as an example, the weakly symmetric dual cobalt (Co2 ) dual J-T sites, weakly asymmetric Fe&Co sites and strongly asymmetric Cu&Co sites were assembled. After illumination, the interaction between dual J-T sites and the CO2 molecules enhances J-T distortion, which further modulates the PCR activity and selectivity. As a result, the Cu&Co sites exhibited CO yield of 8137.9 µmol g-1 , about 2.3-fold and 4.2-fold higher than that of the Fe&Co and Co2 sites within 5-hour photoreaction, respectively. In addition, the selectivity achieved as high as 92.62 % than Fe&Co (88.67 %) and Co2 sites (55.33 %). This work provides a novel design concept for the construction of dual J-T sites to regulate the catalytic activity and selectivity.

Robust and Highly Efficient Electrochemical Hydrogen Production from Hydrazine-Assisted Water Electrolysis Enabled by the Metal-Support Interaction of Ru/C Composites.

Hydrazine oxidation-assisted water electrolysis provides a promising way for the energy-efficient electrochemical hydrogen (H2) and synchronous decomposition of hydrazine-rich wastewater, but the development of highly active catalysts still remains a great challenge. Here, we demonstrate the robust and highly active Ru nanoparticles supported on the hollow N-doped carbon microtube (denoted as Ru NPs/H-NCMT) composite structure as HER and HzOR bifunctional electrocatalysts. Thanks to such unique hierarchical architectures, the as-synthesized Ru NPs/H-NCMTs exhibit prominent electrocatalytic activity in the alkaline condition, which needs a low overpotential of 29 mV at 10 mA cm-2 for HER and an ultrasmall working potential of -0.06 V (vs RHE) to attain the same current density for HzOR. In addition, assembling a two-electrode hybrid electrolyzer using as-prepared Ru NPs/H-NCMT catalysts shows a small cell voltage of mere 0.108 V at 100 mA cm-2, as well as the remarkable long-term stability. Density functional theory calculations further reveal that the Ru NPs serve as the active sites for both the HER and HzOR in the nanocomposite, which facilitates the adsorption of H atoms and hydrazine dehydrogenation kinetics, thus enhancing the performances of HER and HzOR. This work paves a novel avenue to develop efficient and stable electrocatalysts toward HER and HzOR that promises energy-saving hybrid water electrolysis electrochemical H2 production.

Self-Polarization Triggered Multiple Polar Units Toward Electrochemical Reduction of CO2 to Ethanol with High Selectivity.

Electrochemical conversion of CO2 to highly valuable ethanol has been considered a intriguring strategy for carbon neutruality. However, the slow kinetics of coupling carbon-carbon (C-C) bonds, especially the low selectivity ethanol than ethylene in neutral conditions, is a significant challenge. Herein, the asymmetrical refinement structure with enhanced charge polarization is built in the vertically oriented bimetallic organic frameworks (NiCu-MOF) nanorod array with encapsulated Cu2 O (Cu2 O@MOF/CF), which can induce an intensive internal electric field to increase the C-C coupling for producing ethanol in neutral electrolyte. Particularly, when directly employed Cu2 O@MOF/CF as the self-supporting electrode, the ethanol faradaic efficiency (FEethanol ) could reach maximum 44.3 % with an energy efficiency of 27 % at a low working-potential of -0.615 V versus the reversible hydrogen electrode (vs. RHE) using CO2 -saturated 0.5 M KHCO3 as the electrolyte. Experimental and theoretical studies suggest that the polarization of atomically localized electric fields derived from the asymmetric electron distribution can tune the moderate adsorption of *CO to assist the C-C coupling and reduce the formation energy of H2 CCHO*-to-*OCHCH3 for the generation of ethanol. Our research offers a reference for the design of highly active and selective electrocatalysts for reducing CO2 to multicarbon chemicals.

Selective Adsorption Behavior Modulation on Nickel Selenide by Heteroatom Implantation and Heterointerface Construction Achieves Efficient Co-production of H2 and Formate.

Glycerol-assisted hybrid water electrolysis is a potential strategy to achieve energy-efficient hydrogen production. However, the design of an efficient catalyst for the specific reaction is still a key challenge, which suffers from the barrier of regulating the adsorption characteristics of distinctive intermediates in different reactions. Herein, a novel rationale that achieves selective adsorption behavior modulation for self-supported nickel selenide electrode by heteroatom implantation and heterointerface construction through electrodeposition is developed, which can realize nichetargeting optimization on hydrogen evolution reaction (HER) and glycerol oxidation reaction (GOR), respectively. Specifically, the prepared Mo-doped Ni3 Se2 electrode exhibits superior catalytic activity for HER, while the NiSe-Ni3 Se2 electrode exhibits high Faradaic efficiency (FE) towards formate production for GOR. A two-electrode electrolyzer exhibits superb activity that only needs an ultralow cell voltage of 1.40 V to achieve 40 mA cm-2 with a high FE (97%) for formate production. Theoretical calculation unravels that the introduction of molybdenum contributes to the deviation of the d-band center of Ni3 Se2 from the Fermi level, which is conducive to hydrogen desorption. Meanwhile, the construction of the heterojunction induces the distortion of the surface structure of nickel selenide, which exposes highly active nickel sites for glycerol adsorption, thus contributing to the excellent electrocatalytic performance.

Electrochemical Biomass Upgrading Coupled with Hydrogen Production under Industrial-Level Current Density.

As promising hydrogen energy carrier, formic acid (HCOOH) plays an indispensable role in building a complete industry chain of a hydrogen economy. Currently, the biomass upgrading assisted water electrolysis has emerged as an attractive alternative for co-producing green HCOOH and H2 in a cost-effective manner, yet simultaneously affording high current density and Faradaic efficiency (FE) still remains a big challenge. Here, the ternary NiVRu-layered double hydroxides (LDHs) nanosheet arrays for selective glycerol oxidation and hydrogen evolution catalysis are reported, which yield an industry-level 1 A cm-2 at voltage of 1.933 V, meanwhile showing considerable HCOOH and H2 productivities of 12.5 and 17.9 mmol cm-2  h-1 , with FEs of almost 80% and 96%, respectively. Experimental and theoretical results reveal that the introduced Ru atoms can tune the local electronic structure of Ni-based LDHs, which not only optimizes hydrogen adsorption kinetics for HER, but also reduces the reaction energy barriers for both the conversion of NiII into GOR-active NiIII and carboncarbon (CC) bond cleavage. In short, this work highlights the potential of large-scale H2 and HCOOH productions from integrated electrocatalytic system and provides new insights for designing advanced electrocatalyst for low-cost and sustainable energy conversion.

Arming Ru with Oxygen-Vacancy-Enriched RuO2 Sub-Nanometer Skin Activates Superior Bifunctionality for pH-Universal Overall Water Splitting.

Water electrolysis has been expected to assimilate the renewable yet intermediate energy-derived electricity for green H2 production. However, current benchmark anodic catalysts of Ir/Ru-based compounds suffer severely from poor dissolution resistance. Herein, an effective modification strategy is proposed by arming a sub-nanometer RuO2 skin with abundant oxygen vacancies to the interconnected Ru clusters/carbon hybrid microsheet (denoted as Ru@V-RuO2 /C HMS), which can not only inherit the high hydrogen evolution reaction (HER) activity of the Ru, but more importantly, activate the superior activity toward the oxygen evolution reaction (OER) in both acid and alkaline conditions. Outstandingly, it can achieve an ultralow overpotential of 176/201 mV for OER and 46/6 mV for the HER to reach 10 mA cm-2 in acidic and alkaline solution, respectively. Inspiringly, the overall water splitting can be driven with an ultrasmall cell voltage of 1.467/1.437 V for 10 mA cm-2 in 0.5 m H2 SO4 /1.0 m KOH, respectively. Density functional theory calculations reveal that armoring the oxygen-vacancy-enriched RuO2 exoskeleton can cooperatively alter the interfacial electronic structure and make the adsorption behavior of hydrogen and oxygen intermediates much close to the ideal level, thus simultaneously speeding up the hydrogen evolution kinetics and decreasing the energy barrier of oxygen release.

Construction of Nitrogen-Doped Biphasic Transition-Metal Sulfide Nanosheet Electrode for Energy-Efficient Hydrogen Production via Urea Electrolysis.

Urea-assisted hybrid water splitting is a promising technology for hydrogen (H2 ) production, but the lack of cost-effective electrocatalysts hinders its extensive application. Herein, it is reported that Nitrogen-doped Co9 S8 /Ni3 S2 hybrid nanosheet arrays on nickel foam (N-Co9 S8 /Ni3 S2 /NF) can act as an active and robust bifunctional catalyst for both urea oxidation reaction (UOR) and hydrogen evolution reaction (HER), which could drive an ultrahigh current density of 400 mA cm-2 at a low working potential of 1.47 V versus RHE for UOR, and gives a low overpotential of 111 mV to reach 10 mA cm-2 toward HER. Further, a hybrid water electrolysis cell utilizing the synthesized N-Co9 S8 /Ni3 S2 /NF electrode as both the cathode and anode displays a low cell voltage of 1.40 V to reach 10 mA cm-2 , which can be powered by an AA battery with a nominal voltage of 1.5 V. The density functional theory (DFT) calculations decipher that N-doped heterointerfaces can synergistically optimize Gibbs free energy of hydrogen and urea, thus accelerating the catalytic kinetics of HER and UOR. This work significantly advances the development of the promising cobalt-nickel-based sulfide as a bifunctional electrocatalyst for energy-saving electrolytic H2 production and urea-rich innocent wastewater treatment.

Tailoring Nitrogen Species in Disk-Like Carbon Anode Towards Superior Potassium Ion Storage.

Carbon materials, as promising anode candidates for K+ storage due to their low cost, abundant sources, and high physicochemical stability, however, encounter limited specific capacity and unfavorable cycling stability that seriously hinder their practical applications. Herein, a feasible strategy to tailor and stabilize the nitrogen species in unique P/N co-doped disk-like carbon through the Sn incorporation (P/NSn -CD) is presented, which can largely enhance the specific capacity and cycling capability for K+ storage. Specifically, it delivers a high specific capacity of 439.3 mAh g-1 at 0.1 A g-1 and ultra-stable cycling capability with a capacity retention of 93.5% at 5000 mA g-1 over 5000 cycles for K+ storage. The underlying mechanism for the superior K+ storage performance is investigated by systematical experimental data combined with theoretical simulation results, which can be derived from the increased edge-nitrogen species, improved content and stability of P/N heteroatoms, and enhanced ionic/electronic kinetics. After coupling P/NSn -CD anode with activated carbon cathode, the KIHCs can deliver a high energy density of 171.7 Wh kg-1 at 106.8 W kg-1 , a superior power density (14027.0 W kg-1 with 31.2 Wh kg-1 retained), and ultra-stable lifespan (89.7% retention after 30 K cycles with cycled at 2 A g-1 ).

Phase-Selective Synthesis of Ruthenium Phosphide in Hybrid Structure Enables Efficient Hybrid Water Electrolysis Under pH-Universal Conditions.

Hydrazine-assisted hybrid water electrolysis is an energy-saving approach to produce high-purity hydrogen, whereas the development of pH-universal bifunctional catalysts encounters a grand challenge. Herein, a phase-selective synthesis of ruthenium phosphide compounds hybrid with carbon forming pancake-like particles (denoted as Rux P/C-PAN, x = 1 or 2) is presented. The obtained RuP/C-PAN exhibits the highest catalytic activity among the control samples, delivering ultralow cell voltages of 0.03, 0.27, and 0.65 V to drive 10 mA cm-2 using hybrid water electrolysis corresponding to pH values of 14, 7, and 0, respectively. Theoretical calculation deciphers that the RuP phase displays optimized free energy for hydrogen adsorption and reduced energy barrier for hydrazine dehydrogenation. This work may not only open up a new avenue in exploring universally compatible catalyst to transcend the limitation on the pH value of electrolytes, but also push forward the development of an energy-saving hydrogen generation technique based on emerging hybrid water electrolysis.

NASICON-Structured LiZr2(PO4)3 Surface Modification Improves Ionic Conductivity and Structural Stability of LiCoO2 for a Stable 4.6 V Cathode.

Lithium cobalt oxide (LCO) as a classic layered oxide cathode for lithium-ion batteries is limited by the cutoff voltage, which only delivers about half of the theoretical capacity (∼4.2 V, 140 mA h g-1). Recently, raising the cutoff voltage to 4.6 V has been considered to further improve its specific capacity. However, LCO suffers from serious phase transition of O3 to H1-3, which leads to dramatic volume change and loss of cobalt, finally resulting in rapid capacity decay. In this work, we introduce the NASICON-structured LiZr2(PO4)3 (LZP), an ion conductor for lithium ion, to modify the surface of LCO by a wet-chemical method. Such a surface modification improves lithium-ion diffusion between the interface of LCO and electrolyte and restrains the O3 to H1-3 phase transition. As a result, the optimized LCO with 1 wt % coating (denoted as LCO@LZP-1%) demonstrates enhanced electrochemical performance in both half-cell and full-cell. To be specific, LCO@LZP-1% delivers a high specific capacity of 161.3 mA h g-1 and increases the capacity retention from 37.8 to 75.1% within 100 cycles. Importantly, the full-cell assembled by LCO@LZP-1% and artificial graphite can exhibit an outstanding energy density of 345.5 W h kg-1 (based on the total mass of cathode and anode).

Engineering Electronic Transfer Dynamics and Ion Adsorption Capability in Dual-Doped Carbon for High-Energy Potassium Ion Hybrid Capacitors.

Sodium and potassium ions energy storage systems with low cost and high energy/power densities have recently drawn increasing interest as promising candidates for grid-level applications, while the lack of suitable anode materials with fast ion diffusion kinetics highly hinders their development. Herein, we develop a nanoscale confined in situ oxidation polymerization process followed by a conventional carbonization treatment to generate phosphorus and nitrogen dual-doped hollow carbon spheres (PNHCS), which can realize superior sodium and potassium ion storage performance. Importantly, the density functional theory calculation and combined characterizations, e.g., in situ Raman spectroscopy and ex situ X-ray photoelectron spectroscopy, decipher that the P/N doping can enhance the electronic transfer dynamics and ion adsorption capability, which are responsible for enhanced electrochemical performance. Inspiringly, the practicability of the PNHCS anode is demonstrated by assembling the potassium ion hybrid capacitors (KIHCs), where the prominent energy density is 178.80 Wh kg-1 at a power density of 197.65 W kg-1, with excellent cycling stability, can be achieved. This work not only promotes the development of efficient anode material for sodium/potassium ion storage devices but also deciphers the embedded ion storage mechanism.

Mesoporous Single-Crystal Lithium Titanate Enabling Fast-Charging Li-Ion Batteries.

There remain significant challenges in developing fast-charging materials for lithium-ion batteries (LIBs) due to sluggish ion diffusion kinetics and unfavorable electrolyte mass transportation in battery electrodes. In this work, a mesoporous single-crystalline lithium titanate (MSC-LTO) microrod that can realize exceptional fast charge/discharge performance and excellent long-term stability in LIBs is reported. The MSC-LTO microrods are featured with a single-crystalline structure and interconnected pores inside the entire single-crystalline body. These features not only shorten the lithium-ion diffusion distance but also allow for the penetration of electrolytes into the single-crystalline interior during battery cycling. Hence, the MSC-LTO microrods exhibit unprecedentedly high rate capability, achieving a specific discharge capacity of ≈174 mAh g-1 at 10 C, which is very close to its theoretical capacity, and ≈169 mAh g-1 at 50 C. More importantly, the porous single-crystalline microrods greatly mitigate the structure degradation during a long-term cycling test, offering ≈92% of the initial capacity after 10 000 cycles at 20 C. This work presents a novel strategy to engineer porous single-crystalline materials and paves a new venue for developing fast-charging materials for LIBs.

Dual Nanoislands on Ni/C Hybrid Nanosheet Activate Superior Hydrazine Oxidation-Assisted High-Efficiency H2 Production.

Clean hydrogen evolution through electrochemical water splitting underpins various innovative approaches to the pursuit of sustainable energy conversion technologies, but it is blocked by the sluggish anodic oxygen evolution reaction (OER). The hydrazine oxidation reaction (HzOR) has been considered as one of the most promising substitute for OER to improve the efficiency of hydrogen evolution reaction (HER). Herein, we construct novel dual nanoislands on Ni/C hybrid nanosheet array: one kind of island represents the part of bare Ni particle surface, while the other stands for the part of core-shell Ni@C structure (denoted as Ni-C HNSA), in which exposed Ni atoms and Ni-decorated carbon shell perform as active sites for HzOR and HER respectively. As a result, when the current density reaches 10 mA cm-2 , the working potentials are merely -37 mV for HER and -20 mV for HzOR. A two-electrode electrolyzer exhibits superb activity that only requires an ultrasmall cell voltage of 0.14 V to achieve 50 mA cm-2 .