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Exploring advanced electrocatalysts for the hydrazine oxidation reaction (HzOR) could expedite the applications of direct hydrazine fuel cells (DHzFCs) for zero-carbon economics.

A novel bipolar battery architecture using an integrated Al electrode as both the high-capacity anode and bipolar plate is proposed to construct bipolar Li batteries, leading to high energy density and simple architecture/manufacturing.

Mesoporous silicas tethered with anions were developed as quasi-solid electrolytes. The high grafted density of –NTf− groups and their uniformly distributed negative charge endow MCM41-NLiTf with single Li-ion conductivity up to 2.4 × 10−4 S cm−1.

Stable electrode-electrolyte interphases on both electrodes are indispensable to warrant cycling stability of high-voltage Li-metal batteries. Here, we reveal a unique cooperative reaction mechanism to form protective interphase layers on both Li-metal anode and high-voltage cathodes, which is exemplified by a multifunctional additive ethoxy(pentafluoro)cyclotriphosphazene (PFPN). The F-rich PFPN first reacts with Li-metal anode to form LiF-rich solid electrolyte interphase (SEI), which stabilizes the Li deposition/dissolution processes. Meanwhile, the in-situ generated PFPN derivatives with a de-fluorated structure are prone to be oxidized on cathode, forming a robust cathode-electrolyte interphase (CEI) to prevent electrolyte oxidation and electrode degradation at high voltage. With PFPN to harness the aggressive battery electrodes, Li-metal batteries with high-voltage LiCoO2 (4.5 V) and LiNi0.5Mn1.5O2 (4.9 V) cathodes exhibit improved cycling stability and rate capability. In particular, the LiNi0.5Mn1.5O2|Li full cell with limited Li supply (N/P =7.6) demonstrates outperformed capacity retention of 90.7 % after 100 cycles, which is almost twice that of the cell using PFPN-free conventional electrolyte (47.5 %).

Developing advanced electrocatalysts to convert CO2 into liquid fuels such as ethanol is critical for utilizing intermittent renewable energy. The formation of ethanol, however, is generally less f...

Developing highly efficient and low-cost electrocatalysts for the hydrogen evolution reaction (HER) in neutral media is crucial but still a significant challenge on account of the sluggish multistep reaction kinetics involved. Theoretically, constructing a metal/metal hydroxide interface with a metal hydroxide acting as a water dissociation promotor and a metal as the subsequent hydrogen adsorption site is expected to accelerate the HER kinetics in neutral media. We found that the intercalation of tungstate into Ni(OH)2 can tune the electronic structure of the Ni/Ni(OH)2 interface, decrease the energetic barrier for the Volmer step, and thus optimize the HER performance of Ni/Ni(OH)2 hybrid. Herein, a heterostructured Ni/Ni(OH)2 nanosheet array on Cu foam is designed and constructed via a simple hydrothermal and subsequent plasma reduction strategy. The HER performance can be further enhanced by assembling tungstate-intercalated Ni/Ni(OH)2 hybrid nanosheets on Cu2O nanotube arrays, exhibiting a low overpotential (39 mV @ 10 mA cm−2) and excellent stability (48 h).

Transition metal phosphides (TMPs) have been reported as efficient pre-catalysts for the oxygen evolution reaction (OER) in alkaline media. In situ generated metal oxyhydroxides on the surface of TMPs serve as real active sites. However, the reconstruction of most of the reported TMPs is incomplete and the active components cannot be fully used. Herein, hollow nanostructured Ni5P2/FeP4 nanoboxes (NiFeP NBs) are designed and synthesized as pre-catalysts. During the OER, the NiFeP NBs deeply reconstruct into low-crystalline and ultrathin NiOOH/FeOOH nanosheet assembled nanoboxes (NiOOH/FeOOH NBs). In situ Raman spectroscopy and ex situ characterization studies provide evidence that the hollow nanostructure facilitates the deep reconstruction of NiFeP NBs. Benefiting from the hierarchical hollow structure, the abundant interface between NiOOH and FeOOH, and plentiful defects, the reconstructed NiOOH/FeOOH NBs exhibit superior OER activity and excellent stability. Density functional theory (DFT) calculations reveal that the Fe–Ni dual sites in the NiOOH/FeOOH interface may be the possible active sites.

Summary The lithium-metal battery (LMB) holds great promise for various applications for which high energy density is required; the adoption of LMB, however, is limited by poor performance of the lithium-metal anode (LMA), which is intrinsically associated with the unregulated ion transport and reaction. By coating an ion-transport rectifier on the LMA, which was synthesized from a metal-organic framework with high lithium-ion transference number and conductivity, we report here the fabrication of an LMB with a thin Li anode (≤50 μm), a thick LiCoO2 cathode (4 mAh cm−2), and lean electrolyte condition. Such an LMB can potentially deliver high gravimetric and volumetric energy density exceeding that of state-of-the-art lithium-ion batteries. This work offers a new strategy to regulate the ion transport and reaction at electrode-electrolyte interphase, facilitating the development of practical LMB for a broad range of applications.

The sluggish electrochemical kinetics of sulfur species has impeded the wide adoption of lithium-sulfur battery, which is one of the most promising candidates for next-generation energy storage system. Here, we present the electronic and geometric structures of all possible sulfur species and construct an electronic energy diagram to unveil their reaction pathways in batteries, as well as the molecular origin of their sluggish kinetics. By decoupling the contradictory requirements of accelerating charging and discharging processes, we select two pseudocapacitive oxides as electron-ion source and drain to enable the efficient transport of electron/Li+ to and from sulfur intermediates respectively. After incorporating dual oxides, the electrochemical kinetics of sulfur cathode is significantly accelerated. This strategy, which couples a fast-electrochemical reaction with a spontaneous chemical reaction to bypass a slow-electrochemical reaction pathway, offers a solution to accelerate an electrochemical reaction, providing new perspectives for the development of high-energy battery systems., The sluggish electrochemical kinetics of sulfur species remains a major hurdle for the broad adoption of lithium-sulfur batteries. Here, the authors construct an energy diagram of sulfur species to unveil their reaction pathways and propose a general strategy to accelerate electrochemical reactions.

Silicon is one of the most promising anode materials for lithium-ion batteries due to its high theoretical capacity and low cost. However, significant capacity fading caused by severe structural degradation during cycling limits its practical implication. To overcome this barrier, we design a covalently bonded nanocomposite of silicon and poly(vinyl alcohol) (Si-PVA) by high-energy ball-milling of a mixture of micron-sized Si and PVA. The obtained Si nanoparticles are wrapped by resilient PVA coatings that covalently bond to the Si particles. In such nanostructures, the soft PVA coatings can accommodate the volume change of the Si particles during repeated lithiation and delithiation. Simultaneously, as formed covalent bonds enhance the mechanical strength of the coatings. Due to the significantly improved structural stability, the Si-PVA composite delivers a lifespan of 100 cycles with a high capacity of 1526 mAh g-1. In addition, a high initial Coulombic efficiency of over 86% and an average value of 99.2% in subsequent cycles can be achieved. This reactive ball-milling strategy provides a low-cost and scalable route to fabricate high-performance anode materials.

Highlights Nanocapsules made from metal–organic frameworks were designed for sustained release of additive (LiNO3) to passivate Li anode in commercial carbonate-based electrolyte.The nanocapsules with continuous supply of LiNO3 formed a nitride-rich solid electrolyte interphase layer on Li anode and persistently remedied the interphase during prolonged cycling.The practical Li-metal full cell delivered a prolonged lifespan with 90% capacity retention after 240 cycles which has been hardly achieved in commercial electrolyte. Electronic supplementary material The online version of this article (10.1007/s40820-020-00514-1) contains supplementary material, which is available to authorized users., A robust solid-electrolyte interphase (SEI) enabled by electrolyte additive is a promising approach to stabilize Li anode and improve Li cycling efficiency. However, the self-sacrificial nature of SEI forming additives limits their capability to stabilize Li anode for long-term cycling. Herein, we demonstrate nanocapsules made from metal–organic frameworks for sustained release of LiNO3 as surface passivation additive in commercial carbonate-based electrolyte. The nanocapsules can offer over 10 times more LiNO3 than the solubility of LiNO3. Continuous supply of LiNO3 by nanocapsules forms a nitride-rich SEI layer on Li anode and persistently remedies SEI during prolonged cycling. As a result, lifespan of thin Li anode in 50 μm, which experiences drastic volume change and repeated SEI formation during cycling, has been notably improved. By pairing with an industry-level thick LiCoO2 cathode, practical Li-metal full cell demonstrates a remarkable capacity retention of 90% after 240 cycles, in contrast to fast capacity drop after 60 cycles in LiNO3 saturated electrolyte. Electronic supplementary material The online version of this article (10.1007/s40820-020-00514-1) contains supplementary material, which is available to authorized users.

Recycling spent lithium-ion batteries (LIBs) is an urgent task in view of the resource shortage and environmental concerns. Here, a facile ternary molten salt approach is presented for efficiently regenerating the LiNi

The electrochemical reduction of CO to methanol is a potentially cost-effective strategy to reduce the concentration of this greenhouse gas while at the same time producing a value-added chemical. Herein, we detail a highly efficient 2D nickel organic framework containing a large density of highly dispersed salophen NiNO active sites toward electrochemical CORR to methanol. By tuning the ligand environment of the salophen NiNO, the electrocatalytic activity of the material toward CO reduction can be significantly improved. We prove that by introducing a carbonyl group at the ligand environment of the Ni active sites, the electrochemical CO reduction activity is highly promoted and its product selectivity reaches a Faradaic efficiency of 27% toward the production of methanol at − 0.9 V vs RHE. The salophen-based π-d conjugated metal-organic framework presented here thus provides the best performance toward CO reduction to methanol among the previously developed nickel-based electrocatalysts., ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program. Z. Liang acknowledges funding from MINECO SO-FPT PhD grant (SEV-2013-0295-17-1). This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 823717-ESTEEM3. The present work is supported by the I+D+I projects PID2019-105490RB-C32 and NANOGEN (PID2020-116093RB-C43), funded by MCIN/AEI/10.13039/501100011033/ and by “ERDF A way of making Europe”, by the “European Union”. X. Wang thanks the China Scholarship Council for the scholarship support. P. Tang acknowledges the Humboldt Research Fellowship. Authors acknowledge funding from Generalitat de Catalunya 2017SGR327 and 2017SGR1246. L. L acknowledges the support from Natural Sciences and Engineering Research Council Canada (NSERC, DG RGPIN-2020-06675). J. Llorca is a Serra Húnter Fellow and is grateful to MICINN/FEDER RTI2018-093996-B-C31, GC 2017 SGR 128 and to ICREA Academia Program. XAFS measurements were performed at the Canadian Light Source, a national research facility at the University of Saskatchewan, which is supported by the Canada Foundation for Innovation (CFI), the Natural Sciences and Engineering Research Council (NSERC), the National Research Council (NRC), the Canadian Institutes of Health Research (CIHR), the Government of Saskatchewan, and the University of Saskatchewan. W. Tang acknowledges the Chinese Postdoctoral Science Foundation (Nos. 2021M691008).This study was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and Generalitat de Catalunya.

A low-temperature and time-efficient plasma reduction strategy is developed to accelerate the hydrogen evolution reaction (HER) and overall water splitting performance of Co(OH)2. Superior HER activity (a small overpotential of 35 mV at 10 mA cm−2) and excellent overall water splitting performance (1.48 V at 10 mA cm−2) are achieved.

Owing to its abundance and high theoretical capacity, phosphorus has attracted intense research interest as anode material for lithium-ion batteries. However, the adaption of phosphorus for batteries is still limited by its poor electrochemical performance, which is associated with its poor electronic conductivity and large volume change during charging and discharging. We herein report a facile and cost-effective method, which is based on high-energy mechanical milling, for the synthesis of phosphorus nanoparticles within carbon matrix as high-performance anode materials. Red phosphorus was readily transformed into orthorhombic black phosphorus at ambient temperature and pressure, forming phosphorus nanocrystals homogenously dispersed in carbon matrix. Such composites provide superior electrochemical performance, exhibiting reversible capacity of 1000 mA h g−1 after 300 cycles. Full cells based on such phosphorus-carbon composites against LiNi1/3Co1/3Mn1/3O2 cathode offer a capacity retention of 92% after 200 cycles at 0.5 C.

A new family of solid-like electrolytes was developed by infiltrating MIL-100(Al), an electrochemically stable metal-organic-framework (MOF) material, with liquid electrolytes that contain cations from the 3rd period (Na

The low Li+ transference number (tLi+), or the relatively small proportion of Li+ conductivity with respect to total ionic conductivity, has been identified as a key drawback of binary electrolytes. The lack of approaches to restrain anion mobility results in the poor cyclability of energy-dense electrodes as the high rate of anion movement induces concentration polarization. Herein, we propose regulating the ion conduction behavior using a nanocomposite separator fabricated via the functionalization of a glass fiber (GF) separator with a metal–organic framework (MOF). The open metal sites in the MOF serve as the anchoring sites for anions, and the resulting tLi+ is increased by 100%. The MOF-functionalized nanocomposite separator with high tLi+ substantially improves the electrochemical performance of a Li metal anode, with an areal capacity exceeding 2 mA h cm−2, and intercalation-type electrodes (LiFePO4 and Li4Ti5O12), with high active material loadings of 45 mg cm−2.

Numerous metal oxides (MOs) have been considered as promising electrode materials for electrochemical energy storage devices, including lithium-ion batteries (LIBs) and electrochemical capacitors (ECs), because of their outstanding features such as high capacity/capacitance, low cost, as well as environmental friendliness. However, one major challenge for MO-based electrodes is the poor cycling stability derived from the large volume variation and intense mechanic strain, which are inevitably generated during repeated charge/discharge processes. Nanostructure engineering has proven to be one of the most effective strategies to improve the electrochemical performance of MO-based electrode materials. Among various nanostructures, one-dimensional (1D) metal oxide–carbon hybrid nanostructures might offer some solution for the challenging issues involved in bulk MO-based electrode materials for energy storage devices. Herein, we give an overview of the rational design, synthesis strategies and electrochemical properties of such 1D MO–carbon structures and highlight some of the latest advances in this niche area. It starts with a brief introduction to the development of nanostructured MO-based electrodes. We will then focus on the advanced synthesis and improved electrochemical performance of 1D MO–carbon nanostructures with different configurations, including MO–carbon composite nanowires, core–shell nanowires and hierarchical nanostructures. Lastly, we give some perspective on the current challenges and possible future research directions in this area.

Developing drug delivery platforms that can modulate a tumor microenvironment and deliver multiple therapeutics to targeted tumors is critical for efficient cancer treatment. Achieving these platforms still remains a great challenge. Herein, biodegradable nanocapsules based on MnFe hydroxides (H-MnFe(OH)x) have been developed as a new type of cargo delivery with high loading capacity and catalytic activity, enabling synergetic therapy with promoted efficacy by relieving hypoxia in tumor tissues. As a proof of concept, a photosensitizer (indocyanine green, ICG) and a chemotherapeutic drug (doxorubicin, DOX) are co-loaded in nanocapsules and selectively released upon degradation of the nanocapsules in the acidic tumor microenvironment, and are promoted by near infrared irradiation. Meanwhile, Mn2+/Fe3+ ions released from the degradation of nanocapsules catalyze the conversion of H2O2 in a tumor microenvironment into oxygen, which modulates tumor hypoxia and dramatically boosts multimodal therapies. Remarkable synergistic anticancer outcomes have been demonstrated both in vitro and in vivo, paving the way towards future multifunctional therapeutic platforms.

Conventional liquid electrolytes for lithium batteries usually suffer from irreversible decomposition and safety concerns. Solid state electrolytes (SSEs) have been considered as the key for advanced lithium batteries with improved energy density and safety, whereas challenges remain for polymer and inorganic SSEs. Recently, hybrid solid-state electrolytes (HSSEs) that integrate the merits of different electrolyte systems have been under intensive study. Herein, we summarize the recent progress of HSSEs with different compositions and structures. The design principle of each type of HSSEs are discussed, as well as their ionic conducting mechanism, electrochemical performance and effects of compositional/structural control. Finally, challenges and perspectives are provided for the future development of HSSEs and solid-state lithium batteries.

Lithium ion capacitors (LICs) hold potentials to bridge the gap between lithium ion batteries and supercapacitors ; however, the imbalance of electrochemical kinetic and stability between Li + storage anode and capacitive cathode has been the key bottleneck. Herein, we report a high-rate and ultrastable anode for this issue, consisting of boron-doped nanoporous carbon spheres which are synthesized by a continuous spraying-assisted co-assembly process. Experimental and computational investigations as well as the comparison with a nitrogen-rich carbon indicate that boron species enhances ion-surface interactions, electron/ion conductivity and carbon framework cycling firmness, leading to dramatically improved rate and cycling performances, which outperform the extensively explored nitrogen doped carbons and most reported high-rate anode materials . By pairing a coal-derived microporous graphene cathode, we constructed a full-carbon LIC device exhibiting high energy and power densities (207 Wh kg −1 at 511 W kg−1 and still 136 Wh kg−1 at 17.06 kW kg−1), as well as an unprecedented cycling stability with no capacity decay after 15,000 cycles at 2 A g−1. This work not only offers a fundamental basis to understand the enhanced anode performance by doping boron into carbon framework but also provides an effective strategy to circumvent the kinetic and stability discrepancies between anode and cathode for high-performance LICs.

To circumvent the imbalances of electrochemical kinetics and capacity between Li+ storage anodes and capacitive cathodes for lithium-ion capacitors (LICs), we herein demonstrate an efficient solution by boosting the capacitive charge-storage contributions of carbon electrodes to construct a high-performance LIC. Such a strategy is achieved by the in situ and high-level doping of nitrogen atoms into carbon nanospheres (ANCS), which increases the carbon defects and active sites, inducing more rapidly capacitive charge-storage contributions for both Li+ storage anodes and PF6– storage cathodes. High-level nitrogen-doping-induced capacitive enhancement is successfully evidenced by the construction of a symmetric supercapacitor using commercial organic electrolytes. Coupling a pre-lithiated ANCS anode with a fresh ANCS cathode enables a full-carbon LIC with a high operating voltage of 4.5 V and high energy and power densities thereof. The assembled LIC device delivers high energy densities of 206.7 and 115.4 W...

Electrochemical reduction of carbon dioxide to value-added fuels offers a promising method to solve increasingly serious environmental problems and alleviate energy crisis. Herein, we report a facile method by coating Cu electrode with CeO2 nanoparticles to largely enhance the C2+ products selectivity during CO2 electroreduction. The Faradaic efficiency of C2+ products for optimal CeO2-coated Cu electrode reached a high value of 61 % at -1.05 V vs RHE, and exhibited good stability for over 9 h of CO2 electrolysis. The CeO2 nanoparticles were found to induce oxidative corrosion of the Cu foil, leading to a CuOx layer in contact with the CeO2 nanoparticles. The interface between CeO2 nanoparticles and oxide-derived Cu might be attributed to the enhanced catalytic activity for C2+ products by promoting the C C coupling process.

Electrochemical reduction of carbon dioxide provides a feasible solution to the energy and climate crisis. Bi-based catalysts are promising candidates to electrochemically convert carbon dioxide (CO2) into formic acid or formate. Herein, ligand-stabilized Bi nanosheets are obtained from in-situ electrochemical reduction of a Bi-based metal-organic framework, which exhibit remarkable electrocatalytic performance for CO2 reduction. A high Faradic efficiency of 98 % for formate is achieved at a potential of -0.80 V vs. reversible hydrogen electrode (RHE) with an improved durability over 40 h. The remarkable electrocatalytic activity and stability could be attributed to the in-situ generated catalyst with abundant under-coordinated Bi active sites, which are effectively stabilized by residual ligands adsorbed on surface. This study demonstrates that ligand-stabilized under-coordinated surface sites would be facilely generated from in-situ transformation of metal-organic precursors for highly efficient CO2 conversion.

Construction of metal–organic frameworks with sophisticated nanostructures remains a considerable challenge. Herein, we report the rational design and synthesis of ZIF-67 nanoscaffolds and defected nanocubes co-mediated by dopamine and polyoxometalate. The formation of these sophisticated ZIF-67 nanostructures is achieved through the protection of dopamine and etching of polyoxometalate. As a demonstration, we have converted the ZIF-67 nanoscaffolds incorporated with molybdenum into carbon-coated cobalt–molybdenum mixed selenides (denoted as CoMoSe@C nanoscaffolds) with little alteration in the structure by reacting the ZIF-67 nanoscaffolds with selenium powder at high temperature. Benefiting from their unique structural merits, the CoMoSe@C nanoscaffolds exhibit enhanced lithium storage properties in terms of good cycling performance and superior rate capability.

By virtue of high theoretical sodium storage capacities and low cost, FeP is a prospective anode material for sodium-ion batteries (SIBs). Nevertheless, poor cycling and rate performance greatly limit the application of FeP in practice. Herein, a facile template-engaged method is employed to synthesize copper and carbon-incorporated yolk-shelled FeP (denoted as YS-Cu-FeP@C) spheres. The copper is doped into FeP, while the carbon layer with N-doping is coated on the surface of yolk-shelled FeP spheres. Aided by the unique compositional and structural advantages, the as-synthesized YS-Cu-FeP@C spheres exhibit enhanced electrochemical performance for SIBs, including excellent rate capability (145 mAh g−1 at 10 A g−1) and remarkable long-term cycle performance (up to 900 cycles at 1 A g−1). This work provides a rational design and synthetic strategy to boost the sodium storage properties of metal phosphide-based electrode materials.