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Herein, amorphous molybdenum oxide films are constructed by thermal atomic layer deposition (T‐ALD) and plasma‐enhanced atomic layer deposition (PE‐ALD). The physical and chemical properties of molybdenum oxide films prepared by the two methods are systematically compared by means of film growth law, atomic force microscope, scanning electron microscope, etc. The results show that the amorphous molybdenum oxide physical phase prepared by both ALD methods is MoO3. Compared with T‐ALD MoO3, the growth rate of MoO3 thin films prepared by PE‐ALD is higher. Compared to PE‐ALD MoO3, the MoO3 films prepared by T‐ALD did not have nucleation delayed to a laminar growth mode, resulting in smoother deposited films and contained less impurity carbon. The MoO3 prepared by PE‐ALD contains 7.4% impurity carbon. This carbon‐doped film significantly improves the conductivity of the MoO3 film and shows good electrochemical activity. As expected, the MoO3 films prepared by PE‐ALD show good electrocatalytic oxygen evolution reaction. The overpotential is only 259 mV at 10 mA cm−2 and continues to evolution oxygen for 60 h with almost no attenuation, indicating that carbon doping significantly improves the catalytic intrinsic activity and stability of MoO3. [ABSTRACT FROM AUTHOR]

Nitrogen and phosphorus co‐doped porous carbon plate (NPCP) was prepared by simple pyrolysis carbonization and alkali activation of biomass duckweed NPCP displays the largest specific surface area (SSA) of 2023 m2 g−1, and is rich in pyridine N and P doping, which makes the metal‐free carbon have excellent electrocatalytic oxygen reduction performance. The best NPCP2 shows a half‐wave potential of 0.19 V vs. Ag/AgCl in alkaline electrolyte, and its activity is equivalent to that of commercial platinum carbon (Pt/C). In addition, it shows excellent methanol toxicity resistance and continuous catalytic stability. The experimental results show that the heteroatom doping method obtained by biomass hydroponics has great advantages and great application value in the catalytic field of porous carbon materials. [ABSTRACT FROM AUTHOR]

The commercialization of Li−S batteries is seriously hindered by polysulfides with severe shuttle effect, and the inherent insulating properties and slow reaction kinetics of insoluble Li2S products. Transition metal sulfides (TMSs) have a high adsorption capacity for polysulfides and have been shown to have a strong catalytic effect on polysulfide conversion reactions. This paper reviews the research on the application of Unary TMSs, heterostructures, etc. in Li−S batteries, and gives some research methods for TMD catalysts in Li−S batteries. Finally, it points out the main focuses and direction of future Li−S battery research and development. It aims to provide some insights into the design and manufacture of advanced Li−S batteries for commercial use. [ABSTRACT FROM AUTHOR]

The construction of lithium–sulfur battery cathode materials while simultaneously achieving high areal sulfur‐loading, adequate sulfur utilization, efficient polysulfides inhibition, rapid ion diffusion, etc. remains a major challenge. Herein, an internal regulatory strategy to fabricate the unique walnut‐like yolk–shell carbon flower@carbon nanospheres is presented (WSYCS) as sulfur hosts. The internal carbon flower, suitable cavity, and external carbon layer effectively disperse the insulate sulfur, accommodate volumetric expansion, and confine polysulfides, thus improving the performance of lithium–sulfur batteries. The finite element simulation method also deduces the enhanced Li+ diffusion and lithium–sulfur reaction kinetics. More importantly, WSYCS2 is grafted onto carbon fiber (CF) by electro‐spinning method to form a tandem WSYCS2@CF 3D film as a sulfur host for the free‐standing electrode. The corresponding battery exhibits an extremely high areal capacity of 15.5 mAh cm−2 with a sulfur loading of 13.4 mg cm−2. Particularly, the flexible lithium–sulfur pouch cell delivers a high capacity of 8.1 mAh cm−2 and excellent capacity retention of 65% over 800 cycles at a relatively high rate of 1C, corresponding to a calculated energy density of 539 Wh kg−1 and 591 Wh L−1. This work not only provides guidance for tailoring thick carbon/sulfur electrodes but also boosts the development of practical lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Lithium/sodium‐based batteries have attracted widespread attention because of their high specific capacity and excellent energy density, and have become one of the hottest research directions in energy storage devices. However, the stress accumulated during the continuous electrochemical cycle will cause the inevitable electrode failure, which inhibits the further improvement of battery performance. In order to eliminate/relieve the internal stress problem, a variety of battery material structures have been designed. In the design of battery material structure, the simulation technology is used to conduct battery modeling to predict the experimental results, which effectively reduces the range of parameters. For this reason, this paper first introduces the parameters that need to be considered by establishing stress model. Then, the utilization of simulation technology in the structural design of diverse battery materials is examined in this study. Finally, the future application of simulation technology in the field of energy storage is prospected. This is aimed to encourage the widespread utilization of simulation technology in the energy storage battery industry, with the goal of reducing design‐related energy consumption, enhancing experimental design feasibility, and minimizing experimentation costs. [ABSTRACT FROM AUTHOR]

Lithium metal anode (LMA) is the next generation of high‐performance electrochemical energy storage materials because of its unique advantages (high capacity and low redox potential). However, a discontinuous solid electrolyte interface (SEI) layer and lithium dendrites are formed during battery charging, leading to serious safety problems. For this purpose, researchers have devised many solutions, such as artificial SEI, modified current collector, and lithium alloy layer. Among them, the three‐dimensional (3D) current collector with a high surface area can not only reduce the local current density of lithium deposition but also promote lithium‐ion transfer and nucleation, thus inhibiting dendrite growth. In this progress report, we review the design of the LMA 3D‐structured current collector in accordance with the classification. Firstly, we discuss the latest development of advanced metal current collectors. Secondly, the 3D design of carbon‐based current collectors is summarized to improve the overall performance of lithium metal batteries (LMBs). Finally, the main challenges and development prospects of LMBs' current collectors in the future are discussed. [ABSTRACT FROM AUTHOR]

High entropy alloys (HEAs) are composed of five or more metal elements with similar proportions. Due to the electronic structure among metal elements, they have abundant active sites and have good catalytic activity and stability as materials. Therefore, they have great promise in electrochemical energy storage and electrocatalysis. This paper reviews the preparation and characterization methods of HEAs, and the applications of HEAs in catalysis, especially the contribution in lithium‐sulfur batteries, but also in Electrolyzed water and other energy storage materials. The challenges of HEAs in catalysis and their future developments are also presented. [ABSTRACT FROM AUTHOR]

Herein, we investigated in detail the effect of metal valences in different cobalt‐based organic framework compounds on the kinetics of sulfur reaction in lithium‐sulfur batteries (LSBs). On this basis, two organic framework compounds of zeolite‐imidazole‐based cobalt organic framework compound (Co‐ZIF) and tetrakis(4‐benzoic acid) porphyrinato‐CoIII chloride [Co‐TBP(III)] with different valences were constructed as the functional intercalation separators of LSBs, and explored the effects of different valences on improving the reaction kinetics of polysulfides and inhibiting the shuttle effect. Experiments and theoretical calculations prove that CoII exhibits the best catalytic activity. This is mainly due to the fact that +2 valence shows a strong adsorption energy for polysulfides and a higher Fermi level compared with +3 valence, thus improving the efficiency of the rapid catalytic conversion of sulfur species. As expected, the discharge specific capacity of Co‐ZIF as the catalytic layer of the LSBs reached 772.7 mAh g−1 at a high current density of 5 C. More importantly, the initial specific capacity is 839.6 mAh g−1 at high current 3 C, and after 720 cycles, the attenuation rate of per cycle is only 0.092 %, and the coulombic efficiency remains above 92 %. [ABSTRACT FROM AUTHOR]

Fluorinated solid‐state electrolytes (FSSEs) exhibit good compatibility with positive materials, wide electrochemical windows, and stable chemical stability, which have been widely used in all‐solid‐state lithium batteries (ASSLBs). However, the practical application of fluorinated solid electrolytes still faces great challenges due to factors such as ionic conductivity, chemical stability, and current limitation. Herein, the development history of FSSEs is reviewed first. Subsequently, the recent advances in the improvement of ion conductivity, chemical stability, and current limit by structural design, interface regulation strategies, etc. are analyzed. Finally, the design requirements for future generations of FSSEs are prospected, focusing on the latest simple one‐step synthesis methods, improving the ionic conductivity at room temperature, and optimizing the electrochemical stability window of FSSEs. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting is an effective strategy, which can convert intermittent energy such as wind energy and solar energy into renewable and sustainable hydrogen energy. Global freshwater resources are extremely scarce. Compared with freshwater, seawater is a rich and sustainable resource, and it has attracted more and more attention in electrocatalysis. However, the oxygen evolution reaction (OER) is a four‐electron transfer process, which leads to slow reaction kinetics. Moreover, the presence of various elements in seawater and their interference to electrochemistry make the OER in seawater extremely challenging. Herein, the latest progress in the development of transition metal‐based OER electrocatalytic materials for seawater is reviewed by hydroxides, oxides, chalcogenides, phosphides, and nitrides. Focus is made on how to eliminate competitive reaction chlorine evolution reaction of OER in electrolytic seawater. The recent research advances of OER catalyst for selective electrolysis seawater are summarized from the aspects of structure design, mechanism understanding, and performance enhancement strategy. Finally, the challenges, prospects, and research directions of seawater electrocatalysis for OER are introduced. [ABSTRACT FROM AUTHOR]

Rational design of sulfur hosts for effectively confining lithium polysulfides (LiPS) and optimizing the sluggish sulfur kinetics is still a major challenge in lithium–sulfur batteries (LSBs). In this work, a simple strategy of introducing single Mo–N4 atoms into N‐doped carbon nano‐flower matrix (Mo‐N‐CNF) as sulfur host cathode materials is developed to realize high‐performance LSBs. These single Mo–N4 atoms have been demonstrated to regulate the hydrophilic nature, Li‐ion diffusion, adsorption capacity, and catalytic conversion of polysulfides via experimental evidences and theoretical calculations. The resulting Mo‐N‐CNF with high loading content of sulfur (>72 wt.%) exhibits a high specific capacity (1248 mAh g–1 at 0.2 C) and excellent rate capability (715 mAh g–1 at 5 C). More importantly, the outstanding cycling performance with a low attenuation rate of only 0.004% per cycle over 400 cycles at 4.27 mA cm–2 is achieved with the area sulfur loading of 5.1 mg cm–2. This work demonstrates a viable strategy for using single atoms‐based carbon materials with high exposed sites as multiple captors for LiPS and an efficient accelerator for sulfur redox kinetics toward next‐generation LSBs with boosted electrochemical performance. [ABSTRACT FROM AUTHOR]

We have successfully constructed a new type of intercalation membrane material by covalently grafting organic tris(hydroxypropyl)phosphine (THPP) molecules onto hydroxylated multi‐walled carbon nanotubes (CNT‐OH) as a functional interlayer for the advanced LSBs. The as‐assembled interlayer has been demonstrated to be responsible for the fast conversion kinetics of polysulfides, the inhibition of polysulfide shuttle effect, as well as the formation of a stable solid electrolyte interphase(SEI) layer. By means of spectroscopic and electrochemical analysis, we further found THPP plays a key role in accelerating the conversion of polysulfides into low‐ordered lithium sulfides and suppressing the loss of polysulfides, thus rendering the as‐designed lithium–sulfur battery in this work a high capacity, excellent rate performance and long‐term stability. Even at low temperatures, the capacity decay rate was only 0.036 % per cycle for 1700 cycles. [ABSTRACT FROM AUTHOR]

Reported herein is an active and durable CoN‐containing oxygen evolution reaction (OER) electrocatalyst which efficiently functions in a neutral medium (pH ≈7). The composite material (N, S)‐RGO@CoN is synthesized by delicate atomic layer deposition (ALD) of CoN on a nitrogen and sulfur (N, S) co‐doped reduced graphene oxide (RGO) substrate. Representative results of the comprehensive study are: 1) The flower‐like sphere RGO substrate prepared by spray drying method features rich physical and chemical properties, which are beneficial for rapid mass/charge transfer to improve the intrinsic OER process; 2) the optimal ALD material for OER tests is afforded by tuning spray conditions and ALD parameters. Versatile structural and compositional characterizations confirm uniform growth and strong chemical coupling of nanostructured CoN on (N, S)‐RGO matrix; 3) the material is electrocatalytically active and durable in a neutral electrolyte, recording an OER overpotential of 220 mV at a current density of 10 mA cm−2 and stability of 20 h continuous catalysis at 20 mA cm−2 with nearly 100% Faradic efficiency; 4) Upon the experimental studies and density functional theory calculations, the eventual mechanism of remarkable OER activity conforms to the structural fate of ALD CoN electronic coupling to the carbon substrate. [ABSTRACT FROM AUTHOR]

An efficient and durable oxygen evolution reaction (OER) electrocatalyst consisting of TiN @ Co5.47N is constructed by the integration of plasma nitriding and a delicate atomic layer deposition (ALD) CoxN process. Representative results of comprehensive study are: 1) the material is electrocatalytically active in universal medium. The OER overpotentials are 398, 248, and 411 mV in acidic, basic, and neutral electrolyte, respectively, at a current density of 50 mA cm−2; 2) the material records an impressive long‐term stability of continuous catalysis for 1500 h, during which the overpotential increases by only 1.3%. The synergistically electronic interaction between TiN and ALD Co5.47N, as well as a protective yet active CoTi layered double hydroxides (CoTi LDH) layer formed simultaneously at the interface/surface of TiN @ Co5.47N during the electrocatalytic process, is speculated to be responsible for the superior OER performance; 3) the surface Co atoms other than Ti of CoTi LDH, exhibit electrocatalytic activity with dramatically low overpotential based on density functional theory calculations. [ABSTRACT FROM AUTHOR]

Rational design of hollow micro‐ and/or nano‐structured cathodes as sulfur hosts has potential for high‐performance lithium‐sulfur batteries. However, their further commercial application is hindered because infusing sulfur into hollow hosts is hard to control and the interactions between high loading sulfur and electrolyte are poor. Herein, we designed hierarchical porous hollow carbon nanospheres with radially inwardly aligned supporting ribs to mitigate these problems. Such a structure could aid the sulfur infusion and maximize sulfur utilization owing to the well‐ordered pore channels. This highly organized internal carbon skeleton can also enhance the electronic conductivity. The hollow carbon nanospheres with further nitrogen‐doping as the sulfur host material exhibit good capacity and excellent cycling performance (0.044 % capacity degradation per each cycle for 1000 cycles). [ABSTRACT FROM AUTHOR]

Abstract: Molybdenum carbide (Mo2C) is recognized as an alternative electrocatalyst to noble metal for the hydrogen evolution reaction (HER). Herein, a facile, low cost, and scalable method is provided for the fabrication of Mo2C‐based eletrocatalyst (Mo2C/G‐NCS) by a spray‐drying, and followed by annealing. As‐prepared Mo2C/G‐NCS electrocatalyst displays that ultrafine Mo2C nanopartilces are uniformly embedded into graphene wrapping N‐doped porous carbon microspheres derived from chitosan. Such designed structure offer several favorable features for hydrogen evolution application: 1) the ultrasmall size of Mo2C affords a large exposed active sites; 2) graphene‐wrapping ensures great electrical conductivity; 3) porous structure increases the electrolyte–electrode contact points and lowers the charge transfer resistance; 4) N‐dopant interacts with H+ better than C atoms and favorably modifies the electronic structures of adjacent Mo and C atoms. As a result, the Mo2C/G‐NCS demonstrates superior HER activity with a very low overpotential of 70 or 66 mV to achieve current density of 10 mA cm−2, small Tafel slope of 39 or 37 mV dec−1, respectively, in acidic and alkaline media, and high stability, indicating that it is a great potential candidate as HER electrocatalyst. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium batteries (ASSLBs) can overcome many problems in cathode and lithium anode, and it is a very promising safe secondary battery. However, unstable interface problems between electrolyte and electrode and within the electrolyte still restrict its commercial development. Herein, the interface problems are first revealed in ASSLBs and highlight the need to deeply explore the intrinsic failure mechanisms to solve these problems. Subsequently, the three failure mechanisms of ASSLBs: chemical, electrical, and electrochemical failure are broken down, and focus on the impact of the space charge layer problem on the cathode‐electrolyte interface. The effect of the anode physical contact problem on the anode‐electrolyte interface is discussed. Then, recent advances in ASSLBs, cathode and anode interface optimization strategies, and their corresponding electrochemical properties are discussed. Finally, the interface challenges faced by ASSLBs and feasible interface modification strategies are summarized, which provide references for subsequent studies and insights into the design of interface structures for the new generation of high‐performance ASSLBs. [ABSTRACT FROM AUTHOR]