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Data-driven machine learning is a proven technique for battery material discovery and enables the development of sustainable next-generation batteries.

The structure and electrochemical performance of lithium (Li) metal degrade quickly owing to its hostless nature and high reactivity, hindering its practical application in rechargeable high energy density batteries. In order to enhance the electrochemical reversibility of metallic Li, we designed a Li/Li

Metallic magnesium is a promising high-capacity anode material for energy storage technologies beyond lithium-ion batteries. However, most reported Mg metal anodes are only cyclable under shallow cycling (≤1 mAh cm

The interest in CO2 conversion to value-added chemicals and fuels has increased in recent years as part of strategic efforts to mitigate and use the excessive CO2 concentration in the atmosphere. Much attention has been given to developing two-dimensional catalytic materials with high-efficiency CO2 adsorption capability and conversion yield. While several candidates are being investigated, MXenes stand out as one of the most promising catalysts and co-catalysts for CO2 reduction, given their excellent surface functionalities, unique layered structures, high surface areas, rich active sites, and high chemical stability. This review aims to highlight research progress and recent developments in the application of MXene-based catalysts for CO2 conversion to value-added chemicals, paying special attention to photoreduction and electroreduction. Furthermore, the underlying photocatalytic and electrocatalytic CO2 conversion mechanisms are discussed. Finally, we provide an outlook for future research in this field, including photoelectrocatalysis and photothermal CO2 reduction.

International audience; Autonomous atomistic computations are excellent tools to accelerate the development of heterogeneous (electro-)catalysts. In this perspective, we critically review the achieved progress to accelerate high-throughput screening aimed at identifying promising catalyst materials via databases, workflow managers, and machine-learning techniques. Outstanding challenges are also discussed extensively: the modification and stability of catalyst surfaces under realistic reaction conditions is key for meaningful predictions. Furthermore, adequately accounting for solvent effects remains a topic of active research particularly relevant for biomass transformations and electrocatalysis. Finally, efficient, autonomous workflows for investigating active sites of amorphous catalysts remain underdeveloped. The computations can also be supplemented with autonomous laboratories, which allow the performance of sophisticated experiments driven by artificial intelligence-augmented design of experiments, reducing human-time investment for optimizing synthesis and reaction conditions as well as catalyst characterizations. The combination of autonomous computations and laboratories promise to power the dearly needed transition to a sustainable chemical industry.

The development of a conventional electrolyte, based on commercially available magnesium (Mg) salts in organic solvents, remains one of the most challenging quests for rechargeable Mg batteries. Conventional electrolytes typically form a passivation layer on Mg metal anode, necessitating the extensive use of inorganic chloride additives such as MgCl2. Herein, for the first time, we introduce an organic chloride, tetrabutylammonium chloride (TBAC), as a multifunctional electrolyte additive for conventional magnesium triflate (Mg(OTf)2)-based electrolytes. TBAC was found to perform three major roles: (1) enhance Mg(OTf)2 dissociation in aprotic solvent, (2) inhibit the reduction of triflate anions through surface-adsorbed TBA+, and (3) act as a chloride source to form Mg complexes and stabilize the Mg anode-electrolyte interface. The novel electrolyte combination of TBAC and Mg(OTf)2 in 1,2-dimethoxyethane exhibits excellent Mg plating/stripping with Coulombic efficiency of 97.7% over 200 cycles at 0.5 mA cm−2 and 0.5 mAh cm-2. Post-mortem analysis unveils uniform Mg deposition and stable solid electrolyte interphase formation on Mg anode, which enables reversible cycling with Mo6S8 cathode. Together with our findings on another organic chloride additive, 1-ethyl-3-methylimidazolium chloride, and in combination with different electrolyte salts and solvents, we showcase the general promise of high-performance conventional electrolytes for rechargeable Mg batteries.

Sodium-metal anode battery technologies have revolutionized energy storage research. In recent years, new insights have been gained regarding the solid electrolyte interphase (SEI) on a sodium-metal anode; however, several questions remain to be answered, in particular the impact of electrolyte structure on the composition and physicochemical stability of the SEI. In addition, the impact of ion-solvation chemistry on the crystallinity of the SEI warrants a more detailed understanding. This review discusses the crucial aspects of sodium-ion solvation chemistry and its impact on the stability of the SEI. The core principles guiding the design of electrolytes through additives, ion–solvent interaction, and ion-pair formation are highlighted. Future research directions necessary to design a stable sodium-metal anode are also discussed.

A major challenge hindering the practical adoption of room-temperature sodium-sulfur batteries (NaSBs) is polysulfide dissolution and shuttling, which results in irreversible capacity decay and low Coulombic efficiencies. In this work, we demonstrate for the first time NaSBs using a ferrocene-derived amorphous sulfurized cyclopentadienyl composite (SCC) cathode. Polysulfide dissolution is eliminated via covalent bonding between the insoluble short-chain sulfur species and carbon backbone. Control experiments with a metal-free composite analogue determined that the iron species in the SCC does not have a significant role in polysulfide anchoring. Instead, the superior electrochemical performance is attributed to sulfur covalently bonded to carbon and the uniform nanoparticulate morphology of the SCC composite. In the carbonate-based electrolyte, a discharge capacity of 795 mAh g

Machine learning can accelerate the process of electrocatalyst discovery and optimization, especially when incorporated into a closed-loop approach with autonomous laboratories. This review highlights the recent progress and challenges in this field.

Two-dimensional metal dichalcogenides have demonstrated outstanding potential as cathodes for magnesium-ion batteries. However, the limited capacity, poor cycling stability, and severe electrode pulverization, resulting from lack of void space for expansion, impede their further development. In this work, we report for the first time, nickel sulfide (NiS

This article presents a study on the effect of the hydroxyl group position on the electro-oxidation of butanediols, including 1,2-butanediol, 2,3-butanediol, 1,3-butanediol, and 1,4-butanediol. The effect of the hydroxyl group position in butanediols on their electro-oxidation reactivities is investigated by cyclic voltammetry, linear sweep voltammetry, chronopotentiometry and chronoamperometry in 1.0 M KOH. The results show that the closer the two hydroxyl groups are, the higher the reactivity, and the lower the anodic potential butanediol has. Moreover, the oxidation products from chronoamperometry are analyzed by means of HPLC and NMR. Some value-added products, such as 3-hydroxypropionic acid/3-hydroxypropionate, are produced. The DFT calculation indicates that the oxidation of vicinal diols responds to the conversion from a hydroxyl group to a carboxylate group, followed by C-C bond cleavage, where the carbon charge decreases. These results provide an insight into reactant selection for the electrochemical synthesis of value-added chemicals. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) Nanyang Technological University National Research Foundation (NRF) Published version This work was supported by the Singapore Ministry of Education Tier 2 Grants (MOE-T2EP10220-0001), the Singapore National Research Foundation under its Campus for Research Excellence and Technological Enterprise (CREATE) programme and NRF Fellowship (NRF-NRFF2017-04), the Centre of Advanced Catalysis Science and Technology, Nanyang Technological University, and the Agency for Science, Technology and Research (Central Research Fund Award).

Room-temperature sodium-sulfur batteries have potential in stationary applications, but challenges such as loss of active sulfur and low electrical conductivity must be solved. Nitrogen-doped nanocarbon host cathodes have been employed in metal-sulfur batteries: polar interactions mitigate the loss of sulfur, while the conductive nanostructure addresses the low conductivity. Nevertheless, these two properties run contrary to each other as greater nitrogen-doping of nanocarbon hosts is associated with lower conductivity. Herein, we investigate the polarity-conductivity dilemma to determine which of these properties have the stronger influence on cycling performance. Lower carbonization temperatures produce more pyridinic nitrogen and pyrrolic nitrogen, which from density functional theory calculations preferentially bind discharge products (Na2S and short-chain polysulfides). Despite its lower conductivity, the highly doped composite showed better Coulombic efficiency and stability, retaining a high capacity of 980 mAh g(S)-1 after 800 cycles. Our findings represent a paradigm shift where nitrogen-doping should be prioritized in designing shuttle-free, long-life sodium-sulfur batteries.

Metal anodes represent as a prime choice for the coming generation rechargeable batteries with high energy density. However, daunting challenges including electrode volume variation and inevitable side reactions preclude them from becoming a viable technology. Here, a facile replacement reaction was employed to fabricate a three-dimensional (3D) interdigitated metal/solid electrolyte composite electrode, which not only provides a stable host structure for buffering the volume change within the composite but also prevents side reactions by avoiding the direct contact between active metal and liquid electrolyte. As a proof-of-concept demonstration, a 3D interdigitated zinc (Zn) metal/solid electrolyte architecture was fabricated via a galvanic replacement reaction between Zn metal foil and indium (In) chloride solution followed by electrochemical activation, featuring the interdigitation between metallic Zn and amorphous indium hydroxide sulfate (IHS) with high Zn2+ conductivity (56.9 ± 1.8 mS cm-1), large Zn2+ transference number (0.55), and high electronic resistivity [(2.08 ± 0.01) × 103 Ω cm]. The as-designed Zn/IHS electrode sustained stable electrochemical Zn plating/stripping over 700 cycles with a record-low overpotential of 8 mV at 1 mA cm-2 and 0.5 mAh cm-2. More impressively, it displayed cycle-stable performance with low overpotential of 10 mV under ultrahigh current density and areal capacity (20 mA cm-2, 20 mAh cm-2), which outperformed all the reported Zn metal electrodes in mild aqueous electrolyte. The fabrication of interdigitated metal/solid electrolyte was generalized to other metal pairs, including Zn/Sn and Zn/Co, which provide inspiration for next-generation Zn metal batteries with high energy density and reversibility.

Single atom catalysts (SACs) have received much attention in the nitrogen reduction reaction (NRR) field due to their high atomic utilization and controllable electronic state regulation. It is attractive to explore the mechanism for regulating the electronic state of the active center of single-atom catalysts. Herein, we propose a new regulation mechanism by applying a strain that can change the coordination bond length of Cr–N and quantitatively regulate the electronic state of the active center in Cr-SACs. Based on this mechanism, we achieve an ultra-low 0.174 V over-potential for the NRR in the single Cr-embedded nitrogen-doped graphene (CrN3@graphene) by applying lattice stretch of 2.5% compared to the pristine CrN3@graphene. Computational results show that the d band center, the Cr–N anti-bonding orbital and the spin-polarization state of the single Cr atom can be adjusted by tuning the coordination length of Cr–3N. The applied lattice stretch of 2.5% can transform the spin-polarization state of the single Cr atom from a high-spin-polarization state to low-spin-polarization. This conversion weakened the adsorption capacity of N2 for CrN3@graphene and finally achieved an ultra-low over-potential. Our findings open up a new path of NH3 production by exploiting strained SACs under ambient conditions.

The development of highly efficient and durable earth-abundant hydrogen evolution reaction (HER) catalysts is crucial for the extensive implementation of the hydrogen economy. Members of the 2D MXenes family, particularly Mo2CTx, have recently been identified as promising HER catalysts. However, their inherent oxidative instability in air and aqueous electrolyte solutions is hindering their widespread use. Herein, we present a simple and scalable method to circumvent adventitious oxidation in Mo2CTx MXenes via in situ sulfidation to form a Mo2CTx/2H-MoS2 nanohybrid. The intimate epitaxial coupling at the Mo2CTx/2H-MoS2 nanohybrid interface afforded superior HER activities, requiring only 119 or 182 mV overpotential to yield -10 or -100 mA cm-2geom current densities, respectively. Density functional theory calculations reveal strongest interfacial adhesion was found within the nanohybrid structure as compared to the physisorbed nanohybrid, and the possibility to tune the HER overpotential through manipulating the extent of MXene sulfidation. Critically, the presence of 2H-MoS2 suppresses further oxidation of the MXene layer, enabling the nanohybrid to sustain industrially relevant current densities of over -450 mA cm-2geom with exceptional durability. Less than 30 mV overpotential degradation was observed after 10 continuous days of electrolysis at a fixed -10 mA cm-2geom current density or 100,000 successive cyclic voltammetry cycles. The exceptional HER durability of the Mo2CTx/2H-MoS2 nanohybrid presents a major step forward to realize practical implementation of MXenes as noble metal free catalysts for broad-based applications in water splitting and energy conversion.

Electrochemical carbon dioxide reduction reaction (CO2 RR) represents a promising way to generate fuels and chemical feedstock sustainably. Recently, studies have shown that two-dimensional metal carbides and nitrides (MXenes) can be promising CO2 RR electrocatalysts due to the alternating -C and -H coordination with intermediates that decouples scaling relations seen on transition metal catalysts. However, further by tuning the electronic and surface structure of MXenes it should still be possible to reach higher turnover number and selectivities. To this end, defect engineering of MXenes for electrochemical CO2 RR has not been investigated to date. In this work, first-principles modelling simulations are employed to systematically investigate CO2 RR on M2 XO2 -type MXenes with transition metal and carbon/nitrogen vacancies. We found that the -C-coordinated intermediates take the form of fragments (e. g., *COOH, *CHO) whereas the -H-coordinated intermediates form a complete molecule (e. g., *HCOOH, *H2 CO). Interestingly, the fragment-type intermediates become more strongly bound when transition-metal vacancies are present on most MXenes, while the molecule-type intermediates are largely unaffected, allowing the CO2 RR overpotential to be tuned. The most promising defective MXene is Hf2 NO2 containing Hf vacancies, with a low overpotential of 0.45 V. More importantly, through electronic structure analysis it could be observed that the Fermi level of the MXene changes significantly in the presence of vacancies, indicating that the Fermi level shift can be used as an ideal descriptor to rapidly predict the catalytic performance of defective MXenes. Such an evaluation strategy is applicable to other catalysts beyond MXenes, which could enhance high throughput screening efforts for accelerated catalyst discovery.

Lithium-sulfur (Li–S) batteries are appealing energy storage technologies owing to their exceptional energy density. Their practical applications, however, are largely compromised by poor cycling stability and rate capability because of detrimental shuttling of polysulfide intermediates, complicated multiphase sulfur redox reactions, and uncontrolled precipitation of the discharge products (lithium sulfide, Li2S). Herein, monodispersed Co single-atom catalyst on conductive nitrogen-doped carbon nanosheet (CoSA-N-C) with high Co content of 15.3 ​wt% was fabricated through a salt-template method and used as a sulfur host material to simultaneously alleviate the polysulfide shuttling, propel the redox kinetics of dissolved polysulfides, and mediate the deposition of Li2S. The robust two-dimensional architecture of CoSA-N-C with large surface area, high porosity, and dual lithiophilic-sulfiphilic Co–N species enable strong physical and chemical polysulfides confinement and fast electrons/ions transfer process. The densely populated Co–N4 coordinated moieties function as electrocatalytic sites to accelerate the reversible conversion between lithium polysulfides and Li2S. Importantly, the CoSA-N-C enables spatially controlled deposition of Li2S nanoparticles during the battery discharge process, as opposed to conventional Li2S passivation layers that fully covered the conductive host. Consequently, the as-fabricated cathodes based on the CoSA-N-C deliver high sulfur utilization (1574 mAh·g−1 at 0.05 ​C), outstanding rate capability (624 mAh g−1 at 5 ​C) and superior long-term stability (capacity fade rate of 0.035% per cycle for 1000 cycles at 1 ​C). Even under a sulfur loading up to 4.9 ​mg ​cm−2, the reversible areal capacity could reach 4.24 mAh cm−2 after 120 cycles at 0.2 ​C, delivering an ultrahigh capacity retention of 91.8%. This work sheds inspiring insights on the important role of single atomic metal with high mass loading in mediating the deposition of lithium sulfides and accelerating the reversible conversion of lithium polysulfides toward decent-performance Li–S batteries.

Room-temperature sodium–sulfur battery is considered to be a promising candidate for next-generation batteries due to its high theoretical energy density (~1274 ​Wh kg−1) and natural abundance of elements. There are however, a number of concomitant challenges, including large volume change, low ionic conductivity, rapid dendrite growth, and high chemical reactivity, which limit the viability of sodium anodes. Solid electrolyte interphases that address all 4 challenges simultaneously to enable high-rate cycling of sodium anodes remain scarce in the literature. Here we report an artificial metal-alloy interphase (MAI) comprising sodium-tin alloy, which was synthesized using a facile solid-vapor reaction of metallic sodium with tin tetrachloride vapors, instead of using typical liquid electrolytes with tin-based additives (solid-liquid reaction). The MAI was found to facilitate reversible deposition of sodium at relatively high current densities (2–7 ​mA ​cm−2), and allows sodium electrodes to cycle stably for over 650 cycles at 2 ​mA ​cm−2 in sodium symmetric cells. Owing to the unique properties of MAI, such as strong electrode adhesion (to accommodate volume change), high ionic conductivity (to minimize overpotential), high Young’s modulus (to suppress dendrite growth), and low electrolyte permeability (to minimize electrolyte reduction), the sodium anode with MAI can endure extended cycling test in sodium–sulfur batteries for over 500 cycles with a high Coulombic efficiency of 99.7%. This solid-vapor chemistry concept to synthesize MAIs can also be generalized to other material systems such as sodium-silicon and sodium-titanium alloys.

The initial lithium loss in lithium-ion batteries (LIBs) reduces their energy density (e.g., 15% or higher for LIBs using a Si-based anode). Herein, we report in situ chemical formation of a confor...

A reliable energy storage ecosystem is imperative for a renewable energy future, and continued research is needed to develop promising rechargeable battery chemistries. To this end, better theoretical and experimental understanding of electrochemical mechanisms and structure-property relationships will allow us to accelerate the development of safer batteries with higher energy densities and longer lifetimes. This Review discusses the interplay between theory and experiment in battery materials research, enabling us to not only uncover hitherto unknown mechanisms but also rationally design more promising electrode and electrolyte materials. We examine specific case studies of theory-guided experimental design in lithium-ion, lithium-metal, sodium-metal, and all-solid-state batteries. We also offer insights into how this framework can be extended to multivalent batteries. To close the loop, we outline recent efforts in coupling machine learning with high-throughput computations and experiments. Last, recommendations for effective collaboration between theorists and experimentalists are provided.