Colossal Granular Lithium Deposits Enabled by the Grain-Coarsening Effect for High-Efficiency Lithium Metal Full Batteries

The low Coulombic efficiency of the lithium metal anode is recognized as the real bottleneck to practical high-efficiency lithium metal batteries with limited Li excess. The grain size and microstructure of deposited lithium strongly influences the lithium plating/stripping efficiency. Here, a solubilizer-mediated carbonate electrolyte that can realize grain coarsening of lithium deposits (>20 µm in width) with oriented columnar morphology, which is in sharp contrast with conventional nanoscale dendrite-like lithium deposits in carbonate electrolytes, is reported. It exhibits improved Li Coulombic efficiency to 98.14% at a high capacity of 3 mAh cm⁻² over 150 cycles, because the colossal lithium deposition with minimal tortuosity can maintain the bulk Li with continuous electron conducting pathway during the stripping process, thus enabling efficient Li utilization. Li/NMC811 full batteries, composed of thin Li anode (45 µm) and a high-capacity NMC811 cathode (16.7 mg cm⁻²), can achieve at least 12 times longer lifespan (200 cycles).     

High-Safety and High-Energy-Density Lithium Metal Batteries in a Novel Ionic-Liquid Electrolyte

Rechargeable lithium metal batteries are next generation energy storage devices with high energy density, but face challenges in achieving high energy density, high safety, and long cycle life. Here, lithium metal batteries in a novel nonflammable ionic-liquid (IL) electrolyte composed of 1-ethyl-3-methylimidazolium (EMIm) cations and high-concentration bis(fluorosulfonyl)imide (FSI) anions, with sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) as a key additive are reported. The Na ion participates in the formation of hybrid passivation interphases and contributes to dendrite-free Li deposition and reversible cathode electrochemistry. The electrolyte of low viscosity allows practically useful cathode mass loading up to ≈16 mg cm⁻². Li anodes paired with lithium cobalt oxide (LiCoO₂) and lithium nickel cobalt manganese oxide (LiNi_0.8Co_0.1Mn_0.1O₂, NCM 811) cathodes exhibit 99.6–99.9% Coulombic efficiencies, high discharge voltages up to 4.4 V, high specific capacity and energy density up to ≈199 mAh g⁻¹ and ≈765 Wh kg⁻¹ respectively, with impressive cycling performances over up to 1200 cycles. Highly stable passivation interphases formed on both electrodes in the novel IL electrolyte are the key to highly reversible lithium metal batteries, especially for Li–NMC 811 full batteries.     

Shielding Polysulfide Intermediates by an Organosulfur-Containing Solid Electrolyte Interphase on the Lithium Anode in Lithium–Sulfur Batteries

The lithium–sulfur (Li–S) battery is regarded as a promising high-energy-density battery system, in which the dissolution–precipitation redox reactions of the S cathode are critical. However, soluble Li polysulfides (LiPSs), as the indispensable intermediates, easily diffuse to the Li anode and react with the Li metal severely, thus depleting the active materials and inducing the rapid failure of the battery, especially under practical conditions. Herein, an organosulfur-containing solid electrolyte interphase (SEI) is tailored for the stabilizaiton of the Li anode in Li–S batteries by employing 3,5-bis(trifluoromethyl)thiophenol as an electrolyte additive. The organosulfur-containing SEI protects the Li anode from the detrimental reactions with LiPSs and decreases its corrosion. Under practical conditions with a high-loading S cathode (4.5 mg_S cm⁻²), a low electrolyte/S ratio (5.0 µL mg_S⁻¹), and an ultrathin Li anode (50 µm), a Li–S battery delivers 82 cycles with an organosulfur-containing SEI in comparison to 42 cycles with a routine SEI. This work provokes the vital insights into the role of the organic components of SEI in the protection of the Li anode in practical Li–S batteries.     

A Metal–Organic Framework as a Multifunctional Ionic Sieve Membrane for Long-Life Aqueous Zinc–Iodide Batteries

The introduction of the redox couple of triiodide/iodide (I₃⁻/I⁻) into aqueous rechargeable zinc batteries is a promising energy-storage resource owing to its safety and cost-effectiveness. Nevertheless, the limited lifespan of zinc–iodine (Zn–I₂) batteries is currently far from satisfactory owing to the uncontrolled shuttling of triiodide and unfavorable side-reactions on the Zn anode. Herein, space-resolution Raman and micro-IR spectroscopies reveal that the Zn anode suffers from corrosion induced by both water and iodine species. Then, a metal–organic framework (MOF) is exploited as an ionic sieve membrane to simultaneously resolve these problems for Zn–I₂ batteries. The multifunctional MOF membrane, first, suppresses the shuttling of I₃⁻ and restrains related parasitic side-reaction on the Zn anode. Furthermore, by regulating the electrolyte solvation structure, the MOF channels construct a unique electrolyte structure (more aggregative ion associations than in saturated electrolyte). With the concurrent improvement on both the iodine cathode and the Zn anode, Zn–I₂ batteries achieve an ultralong lifespan (>6000 cycles), high capacity retention (84.6%), and high reversibility (Coulombic efficiency: 99.65%). This work not only systematically reveals the parasitic influence of free water and iodine species to the Zn anode, but also provides an efficient strategy to develop long-life aqueous Zn–I₂ batteries.     

A Highly Reversible,Dendrite-Free Lithium Metal Anode Enabled by a Lithium-Fluoride-Enriched Interphase

Metallic lithium is the most competitive anode material for next-generation lithium (Li)-ion batteries. However, one of its major issues is Li dendrite growth and detachment, which not only causes safety issues, but also continuously consumes electrolyte and Li, leading to low coulombic efficiency (CE) and short cycle life for Li metal batteries. Herein, the Li dendrite growth of metallic lithium anode is suppressed by forming a lithium fluoride (LiF)-enriched solid electrolyte interphase (SEI) through the lithiation of surface-fluorinated mesocarbon microbeads (MCMB-F) anodes. The robust LiF-enriched SEI with high interfacial energy to Li metal effectively promotes planar growth of Li metal on the Li surface and meanwhile prevents its vertical penetration into the LiF-enriched SEI from forming Li dendrites. At a discharge capacity of 1.2 mAh cm⁻², a high CE of >99.2% for Li plating/stripping in FEC-based electrolyte is achieved within 25 cycles. Coupling the pre-lithiated MCMB-F (Li@MCMB-F) anode with a commercial LiFePO₄ cathode at the positive/negative (P/N) capacity ratio of 1:1, the LiFePO₄//Li@MCMB-F cells can be charged/discharged at a high areal capacity of 2.4 mAh cm⁻² for 110 times at a negligible capacity decay of 0.01% per cycle.     

Ultrahigh coulombic efficiency electrolyte enables Li||SPAN batteries with superior cycling performance

Raising the coulombic efficiency of lithium metal anode cycling is the deciding step in realizing long-life rechargeable lithium batteries. Here, we designed a highly concentrated salt/ether electrolyte diluted in a fluorinated ether: 1.8 M LiFSI in DEE/BTFE (diethyl ether/bis(2,2,2-trifluoroethyl)ether), which realized an average coulombic efficiency of 99.37% at 0.5 mA cm⁻² and 1 mAh cm⁻² for more than 900 cycles. This electrolyte also maintained a record coulombic efficiency of 98.7% at 10 mA cm⁻², indicative of its ability to provide fast-charging with high cathode loadings. Morphological studies reveal dense, dendrite free Li depositions after prolonged cycling, while surface analyses confirmed the formation of a robust LiF-rich SEI layer on the cycled Li surface. Moreover, we discovered that this ether-based electrolyte is highly compatible with the low-cost, high-capacity SPAN (Sulfurized polyacrylonitrile) cathode, where the constructed Li||SPAN cell exhibited reversible cathode capacity of 579 mAh g⁻¹ and no capacity decay after 1200 cycles. A cell where a high areal loading SPAN electrode (>3.5 mAh cm⁻²) is paired with only onefold excess Li was constructed and cycled at 1.75 mA cm⁻², maintaining a coulombic efficiency of 99.30% for the lithium metal. Computational simulations revealed that at saturation, the Li-FSI complex forms contact ion pairs, with a first solvation shell comprising DEE molecules, and a second solvation shell with a mix of DEE/BTFE. This study provides a path to enable high energy density Li||SPAN batteries with stable cycling.     

Rational Design of a High-Loading Polysulfide Cathode and a Thin-Lithium Anode for Developing Lean-Electrolyte Lithium–Sulfur Full Cells

Lithium-sulfur cells are attractive energy-storage systems because of their high energy density and the electrochemical utilization rates of the high-capacity lithium-metal anode and the low-cost sulfur cathode. The commercialization of high-performance lithium–sulfur cells with high discharge capacity and cyclic stability requires the optimization of practical cell-design parameters. Herein, a carbon structural material composed of a carbon nanotube skeleton entrapping conductive graphene is synthesized as an electrode substrate. The carbon structural material is optimized to develop a high-loading polysulfide cathode with a high sulfur loading capacity (6–12 mg cm⁻²), rate performance (C/10–C/2), and cyclic stability for 200 cycles. A thin lithium anode based on the carbon structural material is developed and exhibits long lithium stripping/plating stability for ≈2500 h with a lithium-ion transference number of 0.68. A lean-electrolyte lithium–sulfur full cell with a low electrolyte-to-sulfur ratio of 6 µL mg⁻¹ is constructed with the designed high-loading polysulfide cathode and the thin lithium anode. The integration of all the critical cell-design parameters endows the lithium–sulfur full cell with a low negative-to-positive capacity ratio of 2.4, while exhibiting stable cyclability with an initial discharge capacity of 550 mAh g⁻¹ and 60% capacity retention after 200 cycles.     

The Interaction in Electrolyte Additives Accelerates Ion Transport to Achieve High-Energy Non-Aqueous Lithium Metal Batteries

Electrolyte engineering is a feasible strategy to realize high energy density lithium metal batteries. However, stabilizing both lithium metal anodes and nickel-rich layered cathodes is extremely challenging. To break through this bottleneck, a dual-additives electrolyte containing fluoroethylene carbonate (10 vol.%) and 1-methoxy-2-propylamine (1 vol.%) in conventional LiPF₆-containing carbonate-based electrolyte is reported. The two additives can polymerize and thus generate dense and uniform LiF and Li₃N-containing interphases on both electrodes’ surfaces. Such robust ionic conductive interphases not only prevent lithium dendrite formation in lithium metal anode but also suppress stress-corrosion cracking and phase transformation in nickel-rich layered cathode. The advanced electrolyte enables Li||LiNi_0.8Co_0.1Mn_0.1O₂ stably cycle for 80 cycles at 60 mA g⁻¹ with a specific discharge capacity retention of 91.2% under harsh conditions.     

High-Energy Interlayer-Expanded Copper Sulfide Cathode Material in Non-Corrosive Electrolyte for Rechargeable Magnesium Batteries

Rechargeable magnesium batteries (RMB) have been regarded as an alternative to lithium-based batteries because of their abundant elemental resource, high theoretical volumetric capacity, and multi-electron redox reaction without the dendrite formation of magnesium metal anode. However, their development is impeded by their poor electrode/electrolyte compatibility and the strong Coulombic effect of the multivalent Mg²⁺ ions in cathode materials. Herein, copper sulfide material is developed as a high-energy cathode for RMBs with a non-corrosive Mg-ion electrolyte. Given the benefit of its optimized interlayer structure, good compatibility with the electrolyte, and enhanced surface area, the as-prepared copper sulfide cathode exhibits unprecedented electrochemical Mg-ion storage properties, with the highest specific capacity of 477 mAh g⁻¹ and gravimetric energy density of 415 Wh kg⁻¹ at 50 mA g⁻¹, among the reported cathode materials of metal oxides, metal chalcogenides, and polyanion-type compounds for RMBs. Notably, an impressive long-term cycling performance with a stable capacity of 111 mAh g⁻¹ at 1 C (560 mA g⁻¹) is achieved over 1000 cycles. The results of the present study offer an avenue for designing high-performance cathode materials for RMBs and other multivalent batteries.     

Redistributing Li-Ion Flux by Parallelly Aligned Holey Nanosheets for Dendrite-Free Li Metal Anodes

Li metal is the most ideal anode material to assemble rechargeable batteries with high energy density. However, nonuniform Li-ion flux during repeated Li plating and stripping leads to continuous Li dendrite growth and dead Li formation, which causes safety risks and short lifetime and thus impedes the commercialization of Li metal batteries. Here, parallelly aligned holey nanosheets on a Li metal anode are reported to simultaneously redistribute the Li-ion flux in the electrolyte and in the solid-electrolyte interphase, which allows uniform Li-ion distribution as well as fast Li-ion diffusion for reversible Li plating and stripping. With holey MgO nanosheets as an example, the protected Li anodes achieve Coulombic efficiency of ≈99% and ultralong-term reversible Li plating/stripping over 2500 h at a high current density of 10 mA cm⁻². A full-cell battery, using the protected anode, a 4 V Li-ion cathode, and a commercial carbonate electrolyte, shows capacity retention of 90.9% after 500 cycles.     

Regulating Li-Ion Transport through Ultrathin Molecular Membrane to Enable High-Performance All-Solid-State–Battery

Solid-state lithium metal batteries with garnet-type electrolyte provide several advantages over conventional lithium-ion batteries, especially for safety and energy density. However, a few grand challenges such as the propagation of Li dendrites, poor interfacial contact between the solid electrolyte and the electrodes, and formation of lithium carbonate during ambient exposure over the solid-state electrolyte prevent the viability of such batteries. Herein, an ultrathin sub-nanometer porous carbon nanomembrane (CNM) is employed on the surface of solid-state electrolyte (SSE) that increases the adhesion of SSE with electrodes, prevents lithium carbonate formation over the surface, regulates the flow of Li-ions, and blocks any electronic leakage. The sub-nanometer scale pores in CNM allow rapid permeation of Li-ions across the electrode–electrolyte interface without the presence of any liquid medium. Additionally, CNM suppresses the propagation of Li dendrites by over sevenfold up to a current density of 0.7 mA cm⁻² and enables the cycling of all-solid-state batteries at low stack pressure of 2 MPa using LiFePO₄ cathode and Li metal anode. The CNM provides chemical stability to the solid electrolyte for over 4 weeks of ambient exposure with less than a 4% increase in surface impurities.     

Stabilizing ultrahigh-nickel layered oxide cathodes for high-voltage lithium metal batteries

Rechargeable lithium (Li) metal batteries (LMBs) with ultrahigh-nickel (Ni) layered oxide cathodes offer a great opportunity for applications in electrical vehicles. However, increasing Ni content inherently arouses a tradeoff between specific capacity and electrochemical cyclability due to the aggressive side reactions with electrolyte contributed by the highly reactive Ni species. Here, a protective and stable cathode/electrolyte interphase featuring enriched and evenly-distributed LiF is in situ formed on ultrahigh-Ni cathode LiNi_0.94Co_0.06O₂ (NC) with an advanced ether-based localized high-concentration electrolyte (LHCE), which concurrently shows good compatibility with Li metal anode. Subsequently, the NC cathode can deliver high capacity retentions of 81.4% after 500 cycles at 25 °C and 91.6% after 100 cycles at 60 °C in the voltage range of 2.8–4.4 V in Li||NC cells at 1C cycling rate (1.5 mA cm⁻²). Meanwhile, the conductive electrode/electrolyte interphases formed in LHCE enable a high reversible capacity of about 209 mAh g⁻¹ at 3C charging rate. This work provides an effective approach and important insight from the perspective of in situ ultrahigh-Ni cathode/electrolyte interphase protection for high energy–density, long-lasting LMBs.     

Molybdenum Boride as an Efficient Catalyst for Polysulfide Redox to Enable High-Energy-Density Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries, despite having high theoretical specific energy, possess many practical challenges, including lithium polysulfide (LiPS) shuttling. To address the issues, here, hydrophilic molybdenum boride (MoB) nanoparticles are presented as an efficient catalytic additive for sulfur cathodes. The high conductivity and rich catalytically active sites of MoB nanoparticles allow for a fast kinetics of LiPS redox in high-sulfur-loading electrodes (6.1 mg cm⁻²). Besides, the hydrophilic properties and good wettability toward electrolyte of MoB can facilitate electrolyte penetration and LiPS redox, guaranteeing a high utilization of sulfur under a lean-electrolyte condition. Therefore, the cells with MoB achieve impressive electrochemical performance, including a high capacity (1253 mA h g⁻¹) and ultralong lifespan (1000 cycles) with a low capacity fade rate of 0.03% per cycle. Also, pouch cells fabricated with the MoB additive deliver an ultrahigh discharge capacity of 947 mA h g⁻¹, corresponding to a low electrolyte-to-capacity ratio of about 4.8 µL (mA h)⁻¹, and remain stable over 55 cycles under practically necessary conditions with a low electrolyte-to-sulfur ratio of 4.5 µL mg⁻¹.     

Early Lithium Plating Behavior in Confined Nanospace of 3D Lithiophilic Carbon Matrix for Stable Solid‐State Lithium Metal Batteries

Considerable efforts are devoted to relieve the critical lithium dendritic and volume change problems in the lithium metal anode. Constructing uniform Li⁺ distribution and lithium “host” are shown to be the most promising strategies to drive practical lithium metal anode development. Herein, a uniform Li nucleation/growth behavior in a confined nanospace is verified by constructing vertical graphene on a 3D commercial copper mesh. The difference of solid‐electrolyte interphase (SEI) composition and lithium growth behavior in the confined nanospace is further demonstrated by in‐depth X‐ray photoelectron spectrometer (XPS) and line‐scan energy dispersive X‐ray spectroscopic (EDS) methods. As a result, a high Columbic efficiency of 97% beyond 250 cycles at a current density of 2 mA cm^?2 and a prolonged lifespan of symmetrical cell (500 cycles at 5 mA cm^?2) can be easily achieved. More meaningfully, the solid‐state lithium metal cell paired with the composite lithium anode and LiNi_0.5Co_0.2Mn_0.3O₂ (NCM) as the cathode also demonstrate reduced polarization and extended cycle. The present confined nanospace–derived hybrid anode can further promote the development of future all solid‐state lithium metal batteries.     

Improved Cycling of Li||NMC811 Batteries under Practical Conditions by a Localized High-Concentration Electrolyte

Li||NMC811 battery, with lithium-metal (high specific capacity and low redox potential) as anode and LiNi_0.8Co_0.1Mn_0.1O₂ (NMC811) as cathode, has been widely accepted to be a good candidate as one of the high-energy-density batteries. However, its cyclability needs improvement to fulfill the requirement for its future commercial use, especially under practical conditions. Electrolyte plays a key role in improving the cycling performance of Li||NMC811 batteries, where a high voltage/electrochemical window and good stability with the electrodes of the electrolyte are required. Herein, a localized high-concentration electrolyte with an additive of lithium difluoro(oxalate)borate (LiDFOB) is reported that improves the cycling performance of Li||NMC811 cells under crucial conditions with Li foil thickness of 50 µm, cathode areal loading of 4 mAh cm⁻², the areal capacity ratio between the negative and positive electrodes (N/P ratio) of 2.6 and the electrolyte/cell capacity ratio (E/C ratio) of 3.0 g (Ah)⁻¹. These cells can maintain 80% of the capacity after 195 cycles.     

A High-Voltage,Dendrite-Free,and Durable Zn–Graphite Battery

The intrinsic advantages of metallic Zn, like high theoretical capacity (820 mAh g⁻¹), high abundance, low toxicity, and high safety have driven the recent booming development of rechargeable Zn batteries. However, the lack of high-voltage electrolyte and cathode materials restricts the cell voltage mostly to below 2 V. Moreover, dendrite formation and the poor rechargeability of the Zn anode hinder the long-term operation of Zn batteries. Here a high-voltage and durable Zn–graphite battery, which is enabled by a LiPF₆-containing hybrid electrolyte, is reported. The presence of LiPF₆ efficiently suppresses the anodic oxidation of Zn electrolyte and leads to a super-wide electrochemical stability window of 4 V (vs Zn/Zn²⁺). Both dendrite-free Zn plating/stripping and reversible dual-anion intercalation into the graphite cathode are realized in the hybrid electrolyte. The resultant Zn–graphite battery performs stably at a high voltage of 2.8 V with a record midpoint discharge voltage of 2.2 V. After 2000 cycles at a high charge–discharge rate, high capacity retention of 97.5% is achieved with ≈100% Coulombic efficiency.     

Trapping Lithium Selenides with Evolving Heterogeneous Interfaces for High-Power Lithium-Ion Capacitors

Transition metal selenides anodes with fast reaction kinetics and high theoretical specific capacity are expected to solve mismatched kinetics between cathode and anode in Li-ion capacitors. However, transition metal selenides face great challenges in the dissolution and shuttle problem of lithium selenides, which is the same as Li-Se batteries. Herein, inspired by the density functional theory calculations, heterogeneous can enhance the adsorption of Li₂Se relative to single component selenide electrodes, thus inhibiting the dissolution and shuttle effect of Li₂Se. A heterostructure material (denoted as CoSe₂/SnSe) with the ability to evolve continuously (CoSe₂/SnSe→Co/Sn→Co/Li₁₃Sn₅) is successfully designed by employing CoSnO₃-MOF as a precursor. Impressively, CoSe₂/SnSe heterostructure material delivers the ultrahigh reversible specific capacity of 510 mAh g⁻¹ after 1000 cycles at the high current density of 4 A g⁻¹. In situ XRD reveals the continuous evolution of the interface based on the transformation and alloying reactions during the charging and discharging process. Visualizations of in situ disassembly experiments demonstrate that the continuously evolving interface inhibits the shuttle of Li₂Se. This research proposes an innovative approach to inhibit the dissolution and shuttling of discharge intermediates (Li₂Se) of metal selenides, which is expected to be applied to metal sulfides or Li-Se and Li-S energy storage systems.     

New High Donor Electrolyte for Lithium–Sulfur Batteries

The unparalleled theoretical specific energy of lithium–sulfur (Li–S) batteries has attracted considerable research interest from within the battery community. However, most of the long cycling results attained thus far relies on using a large amount of electrolyte in the cell, which adversely affects the specific energy of Li–S batteries. This shortcoming originates from the low solubility of polysulfides in the electrolyte. Here, 1,3-dimethyl-2-imidazolidinone (DMI) is reported as a new high donor electrolyte for Li–S batteries. The high solubility of polysulfides in DMI and its activation of a new reaction route, which engages the sulfur radical (S₃^•−), enables the efficient utilization of sulfur as reflected in the specific capacity of 1595 mAh g⁻¹ under lean electrolyte conditions of 5 μL_electrolyte mg_sulfur⁻¹. Moreover, the addition of LiNO₃ stabilizes the lithium metal interface, thereby elevating the cycling performance to one of the highest known for high donor electrolytes in Li–S cells. These engineered high donor electrolytes are expected to advance Li–S batteries to cover a wide range of practical applications, particularly by incorporating established strategies to realize the reversibility of lithium metal electrodes.     

Establishing Transition Metal Phosphides as Effective Sulfur Hosts in Lithium–Sulfur Batteries through the Triple Effect of “Confinement–Adsorption–Catalysis”

Structurally optimized transition metal phosphides are identified as a promising avenue for the commercialization of lithium–sulfur (Li–S) batteries. In this study, a CoP nanoparticle-doped hollow ordered mesoporous carbon sphere (CoP-OMCS) is developed as a S host with a “Confinement–Adsorption–Catalysis” triple effect for Li–S batteries. The Li-S batteries with CoP-OMCS/S cathode demonstrate excellent performance, delivering a discharge capacity of 1148 mAh g⁻¹ at 0.5 C and good cycling stability with a low long-cycle capacity decay rate of 0.059% per cycle. Even at a high current density of 2 C after 200 cycles, a high specific discharge capacity of 524 mAh g⁻¹ is maintained. Moreover, a reversible areal capacity of 6.56 mAh cm⁻² is achieved after 100 cycles at 0.2 C, despite a high S loading of 6.8 mg cm⁻². Density functional theory (DFT) calculations show that CoP exhibits enhanced adsorption capacity for sulfur-containing substances. Additionally, the optimized electronic structure of CoP significantly reduces the energy barrier during the conversion of Li₂S₄ (L) to Li₂S₂ (S). In summary, this work provides a promising approach to optimize transition metal phosphide materials structurally and design cathodes for Li–S batteries.