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Although binary Sn-Pb perovskites possess optimal band gap approaching to the Shockley-Queisser limit efficiency, the enhancement on power conversion efficiency (PCE) of Sn-Pb perovskite solar cells (PSCs) is impeded by the detrimental oxidation of Sn

To develop a high-energy-density lithium battery, there still are several severe challenges for Li metal anode: low Coulombic efficiency caused by its high chemical reactivity, Li dendrite formation, and "dead" Li accumulation during repeated plating/stripping processes. Especially, lithium dendrite growth imposes inferior cycling stability and serious safety issues. Herein, we propose a facile but effective strategy to suppress lithium dendrite growth through an artificial inorganic-polymer protective layer derived from sulfurized polyacrylonitrile on a polyethylene separator. Benefiting from the lithiated sulfurized polyacrylonitrile and poly(acrylic acid), the flexible and ion-conductive protective layer could regulate Li

Carbon materials hold the great promise for application in energy storage devices owing to their low cost, high thermal/chemical stability, and high electrical conductivity. However, it remains challenging to synthesize high-performance carbon electrodes in a simple, scalable and sustainable way. Here, we report a facile method for scalable synthesis of porous carbon anode by using cheap and easily accessible zeolitic imidazolate framework-8 as a template and polyvinylpyrrolidone as an additional carbon source. The obtained porous carbon shows the macroscopic sheet-like morphology, which has the highly disordered structure, expanded interlayer spacing, abundant pore structure, and nitrogen doping properties. This porous carbon anode is demonstrated to have the excellent K+ charge storage properties in specific capacity, rate capability, and cycling stability. A potassium-ion capacitor assembled by using this porous carbon as the anode, delivers a maximum energy density of 85.12 Wh/kg and power density of 11860 W/kg as well as long cycle life exceeding 3000 cycles. This represents a critical advance in the design of low cost and scalable carbon material for applications in energy storage devices.

This review summarizes the influence mechanism, research progress and future perspectives on perovskite stability from the perspectives of [PbX6]4− octahedra and organic spacers.

A sodium-ion capacitor is realized using a prelithiated carbon anode instead of the conventional presodiated carbon anode, avoiding the usage of highly reactive metallic sodium and/or sodium containing additives to mitigate sodium loss.

High-entropy alloys (HEAs) are attracting increased attention as an alternative to noble metals for various catalytic reactions. However, it is of great challenge and fundamental importance to develop spatial HEA heterostructures to manipulate d-band center of interfacial metal atoms and modulate electron-distribution to enhance electrocatalytic activity of HEA catalysts. Herein, an efficient strategy is demonstrated to construct unique well-designed HEAs spatial heterostructure electrocatalyst (HEA@Pt) as bifunctional cathode to accelerate oxygen reduction and evolution reaction (ORR/OER) kinetics for Li-O

Inorganic CsPbI2Br perovskites have witnessed incredible advances as a promising representative for translucent and tandem solar cells, but unfortunately, they are still plagued by serious energy losses and undesired phase instability. Herein, a new type of π-conjugated small molecule of 4-guanidinobenzoic-acid-hydrochloride (4-GBACl) is demonstrated to effectively cross-link the Pb-X framework of perovskites. The strong coordination between 4-GBACl and the [PbX6]4- octahedron of perovskites effectively stiffens the Pb-X framework to suppress the ion migration, thus stabilizing the perovskite phase structure against light and thermal conditions. Apart from the physical barrier for phase instability resulting from the hydrophobic benzene ring at grain boundaries (GBs), guanidinium cations and -COOH and Cl- groups can simultaneously afford the passivation of positively and negatively charged defects at the GBs and surface, including undercoordinated halide species and undercoordinated Pb2+ ions, thereby effectively inhibiting the charge trapping/recombination centers. Two-dimensional confocal-fluorescence mapping images provide a visualized sight into the significantly suppressed nonradiative recombination and the prolonged carrier lifetime. It is suggested that the 4-GBACl additive plays multiple roles in grain cross-linking to regulate crystallization, distinctly reducing the trap-state density, ion migration inhibition, and moisture barrier in CsPbI2Br films. Consequently, the 4-GBACl-treated device exhibits a champion power conversion efficiency (PCE) of 15.59% accompanied with a considerably improved Voc of 1.28 V and maintains 88% of the initial PCE value after 1200 h aging under 20% relative humidity.

Developing quasi-solid-state electrolytes with superior ionic conductivity and high mechanical strength is urgently desired to improve the safety and cycling stability of lithium-metal batteries. Herein, a novel solid-like electrolyte (SLE) with enhanced Li

A highly efficient electrocatalyst is a key factor in CO2 conversion using electrochemical methods. Although the single metal catalyst is a key electrocatalyst, its broader application is seriously hindered when it demonstrates unsatisfactory performance. Consequently, how to tune the catalytic capacity of single metal catalysts is an urgent issue that needs to be resolved. In this study, a series of single metal In/C catalysts were synthesized using NaBH4 as a reducing agent, and it was found that the content and crystallinity of In (0) depended on the as-used structure directing agents. Electrochemical tests showed that In/C (CT) synthesized by adding CTAB could effectively reduce CO2 to formic acid with a high Faraday efficiency (89%) of HCOOH at −0.61 V vs. RHE. In the meantime, it presented superior stability during 10 h electrolysis. It was interesting to find that In/C (CA) and In/C (ET) also exhibited better catalytic performance in a wide potential range, which indicated that the crystallinity of indium obviously affected the selectivity and activity during the reduction of CO2 to HCOOH. Furthermore, lower crystallinity of In (0) in In/C (CA) and In/C (ET) led to more efficient catalytic properties in a wide potential range.

Diversified electrochemical energy storage systems highly depend on electrode material construction. In this area, single-atom catalysts intentionally incorporated within two-dimensional (2D) matrices (SAs@2D) can offer desirable advantages derived from host–guest interactions with abundant extrinsic defects. Nevertheless, the intrinsic manipulation mechanisms and guiding insights regarding the use of SAs@2D in various energy storage devices have not been comprehensively appraised. Firstly, newly updated synthesis methodologies and structure–activity mechanisms are summarized in this review. Then, cutting-edge applications regarding the use of SAs@2D hybrids in various rechargeable batteries, such as Li–O2, Li–CO2, Li–S, Li–metal, and Zn–air batteries, and the central kinetics amelioration schemes underlying these applications are highlighted in detail for the first time. We argue that the maximally exposed active centers and optimized electronic environments are responsible for enhancing mass transfer throughout the conductive grid, which is indispensable for accelerating the redox kinetics and enhancing energy efficiencies in advanced battery systems. In particular, in-depth mechanisms describing how high-density unsaturated coordination sites can tune the adsorption-nucleation-growth behaviors of intermediates in the framework and how the impressive electronic and structural characteristics of SAs@2D can lower potential energy barriers during redox reactions are fundamentally concentrated on. Finally, challenges and advisory guidelines for further investigations relating to the use of SAs@2D in rechargeable batteries are presented.

Pseudocapacitive materials with high-rate behavior of lithium-ion charge storage offer a pathway to narrow the kinetics gap with capacitive porous carbon cathode toward lithium-ion capacitors both with high energy and high power densities. However, most of pseudocapacitive materials are subject to their relatively high redox potential and/or the morphological requirement of nanoscale, thus resulting in an undesirable decrease in energy density from either gravimetric or volumetric sides. Here, we demonstrate that lithium-rich disordered rock salt vanadium oxide (DRX-Li3V2O5) exhibits typical pseudocapacitive behaviors within a low working potential range between 0.1 V and 2 V versus a Li/Li+ reference electrode. The pseudocapacitive behaviors of DRX-Li3V2O5 is inherent to its bulk form, which mainly arises upon a percolating network that offers three-dimensional lithium-ion transport pathways confirmed by the Monte Carlo simulations. A lithium-ion capacitor is further assembled by combing this pseudocapacitive DRX-Li3V2O5 anode with a capacitive activated carbon cathode, yields a cell voltage of 4.0 V and both high values of energy and power densities, higher than or comparable to that of the state-of-art lithium-ion capacitors based on graphite and other pseudocapacitive materials. Lithium-ion capacitor based on this high-rate and low-cost DRX-Li3V2O5 anode is ready for commercialization.

Tin (Sn)-based and mixed tin–lead (Sn–Pb) perovskites have attracted increased attention as promising candidates for new generation lead-free perovskite and all-perovskite tandem solar cells. Howev...

Despite high theoretical capacity and earth-abundant resources, the potential industrialization of potassium-sulfur (K-S) batteries is severely plagued by poor electrochemical reaction kinetics and a parasitic shuttle effect. Herein, a facile low-temperature pyrolysis strategy is developed to synthesize N-doped Co nanocluster inlaid porous N-doped carbon derived from ZIF-67 as catalytic cathodes for K-S batteries. To maximize the utilization efficiency, the size of Co nanoparticles can be tuned from 7 nm to homogeneously distributed 3 nm clusters to create more active sites to regulate affinity for S/polysulfides, improving the conversion reaction kinetics between captured polysulfides and K2S3/S, fundamentally suppressing the shuttle effect. Cyclic voltammetry curves, Tafel plots, electrochemical impedance spectroscopy, and density functional theory calculations ascertain that 3 nm Co clusters in S-N-Cos-C cathodes exhibit superior catalytic activity to ensure low charge transfer resistance and energy barriers, enhanced exchange current density, and improved conversion reaction rate. The constructed S-N-Cos-C cathode delivers a superior reversible capacity of 453 mAh g-1 at 50 mA g-1 after 50 cycles, a dramatic rate capacity of 415 mAh g-1 at 400 mA g-1, and a long cycling stability. This work provides an avenue to make full use of high catalytic Co nanoclusters derived from metal-organic frameworks.

Recently, the surge in performance of organic–inorganic hybrid perovskite solar cells (SCs) has boosted the research field of all-inorganic perovskites for their unique substantial stability over h...

Potassium-ion capacitors (KICs) emerge as a promising substitute for the well-developed lithium-ion capacitors (LICs), however, the energy density of KICs is below expectations because of lacking a suitable electrical double-layer positive electrode. Using chemical activation of the Aldol reaction product of acetone with KOH, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 2947 m2/g and a narrow pore size distribution ranging from 1 nm to 3 nm. Half-cell (versus potassium metal) test demonstrates that this porous carbon has high capacitive performance in K+ based organic electrolytes. Furthermore, a novel KIC fabricated by this porous carbon as the cathode, yields high values of energy density and power density. The processes used to make this porous carbon are readily low-cost to fabricate metal-ion capacitors.

Inorganic Na+ conducting solid-state electrolyte (SSE) has received extensive attention in assembling large-scale sodium metal batteries. However, continuous Na dendrites propagation has prevailingly hampered its implementation due to premature cell failure and safety concerns. Herein, a coating layer of AlF3 was decorated between Na anode and NASICON SSE for the first time, which can in situ form a Na+ conducting buffer layer by a conversion reaction with Na during initial cycles. Profiting from the intimate modification of AlF3 interlayer, the Na/SSE interfacial contact is extremely ameliorated. Moreover, owing to the “overpotential triggering” mechanism of the reaction between AlF3 and Na, the locally agminated electron at the anode-electrolyte interface can be released by preferentially driving more Na+ to react with AlF3 instead of forming dendrites at large current density. According to DFT calculations, the critical dendrites length is also enlarged owing to the increased interfacial energy between AlF3-induced interlayer and Na. Therefore, the critical current density of Na/AlF3-NASICON/Na cells has multiplied three-fold to 1.2 ​mA ​cm−2 at 60 ​°C, and the cycling stability of Na metal SSE batteries is also dramatically ameliorated. The rational strategy of modifying AlF3 interlayer is believed to be helpful in resisting dendrites propagation among solid alkalis metal batteries.

The high fluidity and flammability characteristics of the conventional organic liquid electrolyte make it vulnerable for the currently employed commercial lithium batteries to suffer from potential safety risks and premature cell failure. Replacing liquid electrolytes with inorganic solid-state versions coupled with the employment of Li metal anodes is believed to be ideal for next generation energy storage systems with both high security and high energy density. However, even though several promising solid-state electrolytes possess extremely high ionic conductivity, the issues related to a poor electrode/electrolyte interface are a critical constraint. Herein, interface engineering based on current fundamental understanding, challenges, and opportunities of the interface chemistry between inorganic solid-state electrolytes and electrode materials are presented. Firstly, we focus on the interfacial configuration characteristics and mechanisms, pointing out that the unsatisfactory interfacial compatibility and stability, and the dendrite problem are the main drawbacks in achieving high-performance cells, where the interface contact/wettability, constant interfacial reactions, inadequate interfacial Li+ stripping/plating process, and Li dendrite formation/propagation mechanism will be individually reviewed. Then, the recent research status and trends in ameliorating the electrode/electrolyte interface are systematically examined, including the efforts for component optimization and the architectural design of bulk anodes, electrolytes, cathodes, and the interface engineering construction between them. Moreover, several progressive applications and future research directions of interface chemistry will be proposed, aiming to present a comprehensive and enlightening overview for interface engineering that are relevant for the integration of applicable solid-state Li metal batteries.

Potassium-ion batteries (PIBs) are attracting increased attention because of their low cost and similar energy storage mechanism to lithium-ion batteries. Considering the low structural stability and poor electrochemical redox reaction kinetics resulting from the large size of K+ (1.38 A), we elaborately designed novel PDDA-NPCN/Ti3C2 hybrids as PIBs anodes via an electrostatic attraction self-assembly approach, while N-rich porous carbon nanosheets (NPCNs) are derived from metal–hexamine frameworks. The coupled PDDA-NPCN/Ti3C2 hybrids with stacked structure and large specific surface area could ensure intimate contact between Ti3C2 and the NPCNs to efficiently take advantage of both components and more accessible active sites. The hybrids afford enlarged interlayer spacing and unique 3D interconnected conductive networks to accelerate the ionic/electronic transport rates. Meanwhile, the robust hybrids contribute high chemical stabilities due to favorable tolerance to volume change caused by phase transformations during the fast charge/discharge process. DFT calculations further indicate that the PDDA-NPCN/Ti3C2 hybrids efficiently reduce the adsorption energy of K+ and accelerate the reaction kinetics. The hybrids possess a remarkable synergetic effect, leading to a high reversible capacity of 358.4 mA h g−1 after 300 cycles at 0.1 A g−1 and long cycling stability of 252.2 mA h g−1 with only 0.03% degradation per cycle within 2000 cycles at 1.0 A g−1. This work paves the way for further self-assembled coupled hybrids in energy storage devices.

Refereed/Peer-reviewed Arsenic contamination is an increasing global environmental problem, especially in mining industry wastewater where both arsenite (As(III)) and arsenate (As(V)) have been routinely detected. In this paper, a novel porous metal-organic framework material (ZIF-8) was composited with iron nanoparticles (FeNPs) to form a functional material (ZIF-8@FeNPs) for the simultaneous removal of As(III)/(V) from wastewater. The material effectively removed both As(III) and As(V) with removal efficiencies of 99.9 and 71.2%, respectively. Advanced characterization techniques including X-ray photoelectron spectroscopy (XPS) and Fourier infrared (FTIR) indicated that removal of As(III) and As(V) involved complex formation. Adsorption kinetics followed a pseudo-second order kinetics indicating adsorption involved chemisorption. After four cycles of reuse the he removal rate of As species was still relatively high at > 60% When ZIF-8@FeNPs were used to remove As from real wastewater from acid mines the removal efficiency was 94.27%. Finally, a As(III) and As(V) removal mechanism was proposed.

Refereed/Peer-reviewed Arsenic (As) is a contaminant of global concern due to its negative impact on environmental systems, where As occurs mainly as two inorganic species, arsenite (As(III)) and arsenate (As(V)). Thus the simultaneously removal of both As(III) and As(V) from groundwater is a challenging issue. In this paper, zero-valent iron nanoparticles (nZVI) with high surface-active sites were used to simultaneously remove both As(III) and As(V) species from groundwater with removal efficiencies >99.9% for an initial concentration 100 μg L−1. Ion chromatography atomic fluorescence (IC-AFS) analysis indicated that during removal As(III) was oxidized to As(V), while X-ray photoelectron spectroscopy (XPS) showed that the As species were adsorbed on to the surface of nZVI by a complexation reaction. Furthermore, thermodynamic studies of the adsorption process indicated that adsorption was a spontaneous and endothermic chemisorption process. Finally, practical removal of both As species by nZVI from real groundwaters was demonstrated with removal efficiencies of 99.9 and 70.9% for As(V) and As(III), respectively. The presence of other coexisting ions affected the removal efficiency, with phosphate and carbonate decreasing the removal efficiencies of both As(III) and As(V) due competition with active binding sites on the surface of nZVI. Overall, this work demonstrated that nZVI was a promising adsorbent for the practical removal of inorganic As species from complex environmental matrices such as groundwater.