Constructing Three-Dimensional Topological Zn Deposition for Long-Life Aqueous Zn-Ion Batteries

Uniform and compact Zn deposition–dissolution is essential to achieve high Coulombic efficiency and long lifespan for Zn anodes. More attention has been commonly focused on the suppression of macroscopic Zn dendrites in the previous reports. The rational control of the microstructure of Zn deposition to prevent the intrinsic volume expansion and pulverization of Zn metal so as to stabilize Zn anodes is less discussed. Herein, we construct a three-dimensional topological Zn deposition at the nanoscale through an in situ electrochemical process in the optimal hybrid aqueous electrolyte. The topological electrode structure can efficiently accommodate microscopic strain and volume variation and thus largely preserve the macroscopic integrity and electrical contact of Zn anodes, leading to enhanced reversibility and stability. With the unique topological structure of Zn deposition, the Coulombic efficiency of Zn anodes could reach >99.9% with excellent cycling over 1182 h at 2 mA cm–2 and 2 mA h cm–2 (Zn utilization: 11.4%). The evolution of “dead” Zn during repeated cycling is first investigated using a homemade semiquantitative analysis method to determine the critical “short slab” for aqueous Zn batteries under the practical application. This work provides an insightful method to regulate the microscopic morphology of Zn deposition for high-performance Zn batteries

Li⁺‑Desolvation Dictating Lithium-Ion Battery’s Low-Temperature Performances

Lithium (Li) ion battery has penetrated almost every aspect of human life, from portable electronics, vehicles, to grids, and its operation stability in extreme environments is becoming increasingly important. Among these, subzero temperature presents a kinetic challenge to the electrochemical reactions required to deliver the stored energy. In this work, we attempted to identify the rate-determining process for Li⁺ migration under such low temperatures, so that an optimum electrolyte formulation could be designed to maximize the energy output. Substantial increase in the available capacities from graphite∥LiNi_0.80Co_0.15Al_0.05O₂ chemistry down to −40 °C is achieved by reducing the solvent molecule that more tightly binds to Li⁺ and thus constitutes a high desolvation energy barrier. The fundamental understanding is applicable universally to a wide spectrum of electrochemical devices that have to operate in similar environments

Ensemble Effect of Ruthenium Single-Atom and Nanoparticle Catalysts for Efficient Hydrogen Evolution in Neutral Media

Hydrogen evolution reaction (HER) plays a key role in electrochemical water splitting, which is a sustainable way for hydrogen production. The kinetics of HER is sluggish in neutral media that requires noble metal catalysts to alleviate energy consumption during the HER process. Here, we present a catalyst comprising a ruthenium single atom (Ru1) and nanoparticle (Run) loaded on the nitrogen-doped carbon substrate (Ru1-Run/CN), which exhibits excellent activity and superior durability for neutral HER. Benefiting from the synergistic effect between single atoms and nanoparticles in the Ru1-Run/CN, the catalyst exhibits a very low overpotential down to 32 mV at a current density of 10 mA cm–2 while maintaining excellent stability up to 700 h at a current density of 20 mA cm–2 during the long-term test. Computational calculations reveal that, in the Ru1-Run/CN catalyst, the existence of Ru nanoparticles affects the interactions between Ru single-atom sites and reactants and thus improves the catalytic activity of HER. This work highlights the ensemble effect of electrocatalysts for HER and could shed light on the rational design of efficient catalysts for other multistep electrochemical reactions

A Localized High-Concentration Electrolyte with Optimized Solvents and Lithium Difluoro(oxalate)borate Additive for Stable Lithium Metal Batteries

We report a carbonate-based localized high-concentration electrolyte (LHCE) with a fluorinated ether as a diluent for 4-V class lithium metal batteries (LMBs), which enables dendrite-free Li deposition with a high Li Coulombic efficiency (∼98.5%) and much better cycling stability for Li metal anodes than previously reported dimethyl carbonate-based LHCEs at lean electrolyte conditions. This electrolyte consists of 1.2 M lithium bis­(fluorosulfonyl)­imide (LiFSI) in a cosolvent mixture of ethylene carbonate (EC)/ethyl methyl carbonate (EMC) with bis­(2,2,2-trifluoroethyl) ether (BTFE) as the diluent and 0.15 M lithium difluoro­(oxalate)­borate (LiDFOB) as an additive. A Li||LiNi_1/3Mn_1/3Co_1/3O₂ battery with a high areal loading of 3.8 mAh cm^–2 maintains 84% of its initial capacity after 100 cycles. The enhanced stability can be attributed to the robust solid–electrolyte interface (SEI) layer formed on the Li metal anode, arising from the preferential decomposition of LiDFOB salt and EC solvent molecules

Wide-Temperature Electrolytes for Lithium-Ion Batteries

Formulating electrolytes with solvents of low freezing points and high dielectric constants is a direct approach to extend the service-temperature range of lithium (Li)-ion batteries (LIBs). In this study, we report such wide-temperature electrolyte formulations by optimizing the ethylene carbonate (EC) content in the ternary solvent system of EC, propylene carbonate (PC), and ethyl methyl carbonate (EMC) with LiPF₆ salt and CsPF₆ additive. An extended service-temperature range from −40 to 60 °C was obtained in LIBs with lithium nickel cobalt aluminum oxide (LiNi_0.80Co_0.15Al_0.05O₂, NCA) as cathode and graphite as anode. The discharge capacities at low temperatures and the cycle life at room temperature and elevated temperatures were systematically investigated together with the ionic conductivity and phase-transition behaviors. The most promising electrolyte formulation was identified as 1.0 M LiPF₆ in EC–PC–EMC (1:1:8 by wt) with 0.05 M CsPF₆, which was demonstrated in both coin cells of graphite∥NCA and 1 Ah pouch cells of graphite∥LiNi_1/3Mn_1/3Co_1/3O₂. This optimized electrolyte enables excellent wide-temperature performances, as evidenced by the high capacity retention (68%) at −40 °C and C/5 rate, significantly higher than that (20%) of the conventional LIB electrolyte, and the nearly identical stable cycle life as the conventional LIB electrolyte at room temperature and elevated temperatures up to 60 °C

Breaking Low-Strain and Deep-Potassiation Trade-Off in Alloy Anodes via Bonding Modulation for High-Performance K‑Ion Batteries

Alloy anode materials have garnered unprecedented attention for potassium storage due to their high theoretical capacity. However, the substantial structural strain associated with deep potassiation results in serious electrode fragmentation and inadequate K-alloying reactions. Effectively reconciling the trade-off between low-strain and deep-potassiation in alloy anodes poses a considerable challenge due to the larger size of K-ions compared to Li/Na-ions. In this study, we propose a chemical bonding modulation strategy through single-atom modification to address the volume expansion of alloy anodes during potassiation. Using black phosphorus (BP) as a representative and generalizing to other alloy anodes, we established a robust P–S covalent bonding network via sulfur doping. This network exhibits sustained stability across discharge–charge cycles, elevating the modulus of K–P compounds by 74%, effectively withstanding the high strain induced by the potassiation process. Additionally, the bonding modulation reduces the formation energies of potassium phosphides, facilitating a deeper potassiation of the BP anode. As a result, the modified BP anode exhibits a high reversible capacity and extended operational lifespan, coupled with a high areal capacity. This work introduces a new perspective on overcoming the trade-off between low-strain and deep-potassiation in alloy anodes for the development of high-energy and stable potassium-ion batteries

Breaking Low-Strain and Deep-Potassiation Trade-Off in Alloy Anodes via Bonding Modulation for High-Performance K‑Ion Batteries

Alloy anode materials have garnered unprecedented attention for potassium storage due to their high theoretical capacity. However, the substantial structural strain associated with deep potassiation results in serious electrode fragmentation and inadequate K-alloying reactions. Effectively reconciling the trade-off between low-strain and deep-potassiation in alloy anodes poses a considerable challenge due to the larger size of K-ions compared to Li/Na-ions. In this study, we propose a chemical bonding modulation strategy through single-atom modification to address the volume expansion of alloy anodes during potassiation. Using black phosphorus (BP) as a representative and generalizing to other alloy anodes, we established a robust P–S covalent bonding network via sulfur doping. This network exhibits sustained stability across discharge–charge cycles, elevating the modulus of K–P compounds by 74%, effectively withstanding the high strain induced by the potassiation process. Additionally, the bonding modulation reduces the formation energies of potassium phosphides, facilitating a deeper potassiation of the BP anode. As a result, the modified BP anode exhibits a high reversible capacity and extended operational lifespan, coupled with a high areal capacity. This work introduces a new perspective on overcoming the trade-off between low-strain and deep-potassiation in alloy anodes for the development of high-energy and stable potassium-ion batteries

Breaking Low-Strain and Deep-Potassiation Trade-Off in Alloy Anodes via Bonding Modulation for High-Performance K‑Ion Batteries

Alloy anode materials have garnered unprecedented attention for potassium storage due to their high theoretical capacity. However, the substantial structural strain associated with deep potassiation results in serious electrode fragmentation and inadequate K-alloying reactions. Effectively reconciling the trade-off between low-strain and deep-potassiation in alloy anodes poses a considerable challenge due to the larger size of K-ions compared to Li/Na-ions. In this study, we propose a chemical bonding modulation strategy through single-atom modification to address the volume expansion of alloy anodes during potassiation. Using black phosphorus (BP) as a representative and generalizing to other alloy anodes, we established a robust P–S covalent bonding network via sulfur doping. This network exhibits sustained stability across discharge–charge cycles, elevating the modulus of K–P compounds by 74%, effectively withstanding the high strain induced by the potassiation process. Additionally, the bonding modulation reduces the formation energies of potassium phosphides, facilitating a deeper potassiation of the BP anode. As a result, the modified BP anode exhibits a high reversible capacity and extended operational lifespan, coupled with a high areal capacity. This work introduces a new perspective on overcoming the trade-off between low-strain and deep-potassiation in alloy anodes for the development of high-energy and stable potassium-ion batteries

Breaking Low-Strain and Deep-Potassiation Trade-Off in Alloy Anodes via Bonding Modulation for High-Performance K‑Ion Batteries

Alloy anode materials have garnered unprecedented attention for potassium storage due to their high theoretical capacity. However, the substantial structural strain associated with deep potassiation results in serious electrode fragmentation and inadequate K-alloying reactions. Effectively reconciling the trade-off between low-strain and deep-potassiation in alloy anodes poses a considerable challenge due to the larger size of K-ions compared to Li/Na-ions. In this study, we propose a chemical bonding modulation strategy through single-atom modification to address the volume expansion of alloy anodes during potassiation. Using black phosphorus (BP) as a representative and generalizing to other alloy anodes, we established a robust P–S covalent bonding network via sulfur doping. This network exhibits sustained stability across discharge–charge cycles, elevating the modulus of K–P compounds by 74%, effectively withstanding the high strain induced by the potassiation process. Additionally, the bonding modulation reduces the formation energies of potassium phosphides, facilitating a deeper potassiation of the BP anode. As a result, the modified BP anode exhibits a high reversible capacity and extended operational lifespan, coupled with a high areal capacity. This work introduces a new perspective on overcoming the trade-off between low-strain and deep-potassiation in alloy anodes for the development of high-energy and stable potassium-ion batteries

Amorphous Chloride Solid Electrolytes with High Li-Ion Conductivity for Stable Cycling of All-Solid-State High-Nickel Cathodes

Solid electrolytes (SEs) are central components that enable high-performance, all-solid-state lithium batteries (ASSLBs). Amorphous SEs hold great potential for ASSLBs because their grain-boundary-free characteristics facilitate intact solid–solid contact and uniform Li-ion conduction for high-performance cathodes. However, amorphous oxide SEs with limited ionic conductivities and glassy sulfide SEs with narrow electrochemical windows cannot sustain high-nickel cathodes. Herein, we report a class of amorphous Li–Ta–Cl-based chloride SEs possessing high Li-ion conductivity (up to 7.16 mS cm–1) and low Young’s modulus (approximately 3 GPa) to enable excellent Li-ion conduction and intact physical contact among rigid components in ASSLBs. We reveal that the amorphous Li–Ta–Cl matrix is composed of LiCl43–, LiCl54–, LiCl65– polyhedra, and TaCl6– octahedra via machine-learning simulation, solid-state 7Li nuclear magnetic resonance, and X-ray absorption analysis. Attractively, our amorphous chloride SEs exhibit excellent compatibility with high-nickel cathodes. We demonstrate that ASSLBs comprising amorphous chloride SEs and high-nickel single-crystal cathodes (LiNi0.88Co0.07Mn0.05O2) exhibit ∼99% capacity retention after 800 cycles at ∼3 C under 1 mA h cm–2 and ∼80% capacity retention after 75 cycles at 0.2 C under a high areal capacity of 5 mA h cm–2. Most importantly, a stable operation of up to 9800 cycles with a capacity retention of ∼77% at a high rate of 3.4 C can be achieved in a freezing environment of −10 °C. Our amorphous chloride SEs will pave the way to realize high-performance high-nickel cathodes for high-energy-density ASSLBs