An Iron-Decorated Carbon Aerogel for Rechargeable Flow and Flexible Zn–Air Batteries

Mechanically stable and foldable air cathodes with exceptional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities are key components of wearable metal–air batteries. Herein, a directional freeze-casting and annealing approach is reported for the construction of a 3D honeycomb nanostructured, N,P-doped carbon aerogel incorporating in situ grown FeP/Fe₂O₃ nanoparticles as the cathode in a flexible Zn–air battery (ZAB). The aqueous rechargeable Zn–air batteries assembled with this carbon aerogel exhibit a remarkable specific capacity of 648 mAh g⁻¹ at a current density of 20 mA cm⁻² with a good long-term durability, outperforming those assembled with commercial Pt/C+RuO₂ catalyst. Furthermore, such a foldable carbon aerogel with directional channels can serve as a freestanding air cathode for flexible solid-state Zn–air batteries without the use of carbon paper/cloth and additives, giving a specific capacity of 676 mAh g⁻¹ and an energy density of 517 Wh kg⁻¹ at 5 mA cm⁻² together with good cycling stability. This work offers a new strategy to design and synthesize highly effective bifunctional air cathodes to be applied in electrochemical energy devices.     

The Structural and Electronic Engineering of Molybdenum Disulfide Nanosheets as Carbon-Free Sulfur Hosts for Boosting Energy Density and Cycling Life of Lithium–Sulfur Batteries

The compact sulfur cathodes with high sulfur content and high sulfur loading are crucial to promise high energy density of lithium–sulfur (Li–S) batteries. However, some daunting problems, such as low sulfur utilization efficiency, serious polysulfides shuttling, and poor rate performance, are usually accompanied during practical deployment. The sulfur hosts play key roles. Herein, the carbon-free sulfur host composed of vanadium-doped molybdenum disulfide (VMS) nanosheets is reported. Benefiting from the basal plane activation of molybdenum disulfide and structural advantage of VMS, high stacking density of sulfur cathode is allowed for high areal and volumetric capacities of the electrodes together with the effective suppression of polysulfides shuttling and the expedited redox kinetics of sulfur species during cycling. The resultant electrode with high sulfur content of 89 wt.% and high sulfur loading of 7.2 mg cm⁻² achieves high gravimetric capacity of 900.9 mAh g⁻¹, the areal capacity of 6.48 mAh cm⁻², and volumetric capacity of 940 mAh cm⁻³ at 0.5 C. The electrochemical performance can rival with the state-of-the-art those in the reported Li–S batteries. This work provides methodology guidance for the development of the cathode materials to achieve high-energy-density and long-life Li–S batteries.     

Mass-Producible,Quasi-Zero-Strain,Lattice-Water-Rich Inorganic Open-Frameworks for Ultrafast-Charging and Long-Cycling Zinc-Ion Batteries

Low-cost and high-safety aqueous Zn-ion batteries are an exceptionally compelling technology for grid-scale energy storage. However, their development has been plagued by the lack of stable cathode materials allowing fast Zn²⁺-ion insertion and scalable synthesis. Here, a lattice-water-rich, inorganic-open-framework (IOF) phosphovanadate cathode, which is mass-producible and delivers high capacity (228 mAh g⁻¹) and energy density (193.8 Wh kg⁻¹ or 513 Wh L⁻¹), is reported. The abundant lattice waters functioning as a “charge shield” enable a low Zn²⁺-migration energy barrier, (0.66 eV) even close to that of Li⁺ within LiFePO₄. This fast intrinsic ion-diffusion kinetics, together with nanostructure effect, allow the achievements of ultrafast charging (71% state of charge in 1.9 min) and an ultrahigh power density (7200 W kg⁻¹ at 107 Wh kg⁻¹). Equally important, the IOF exhibits a quasi-zero-strain feature (<1% lattice change upon (de)zincation), which ensures ultrahigh cycling durability (3000 cycles) and Coulombic efficiencies of 100%. The cell-level energy and power densities reach ≈90 Wh kg⁻¹ and ≈3320 W kg⁻¹, far surpassing commercial lead–acid, Ni–Cd, and Ni–MH batteries. Lattice-water-rich IOFs may open up new opportunities for exploring stable and fast-charging Zn-ion batteries.     

High-Energy Aqueous Magnesium Ion Batteries with Capacity-Compensation Evolved from Dynamic Copper Ion Redox

The low specific capacity and low voltage plateau are significant challenges in the advancement of practical magnesium ion batteries (MIBs). Here, a superior aqueous electrolyte combining with a copper foam interlayer between anode and separator is proposed to address these drawbacks. Notably, with the dynamic redox of copper ions, the weakened solvation of Mg²⁺ cations in the electrolyte and the enhanced electronic conductivity of anode, which may offer effective capacity-compensation to the 3,4,9,10-perylenetetracarboxylic diimide (PTCDI)-Mg conversion reactions during the long-term cycles. As a result, the unique MIBs using expanded graphite cathode coupled with PTCDI anode demonstrate exceptional performance with an ultra-high capacity (205 mAh g⁻¹, 243 Wh kg⁻¹ at 5 A g⁻¹) as well as excellent cycling stability after 600 cycles and rate capability (138 mAh g⁻¹, 81 Wh kg⁻¹ at 10 A g⁻¹).     

A Carbonyl Compound‐Based Flexible Cathode with Superior Rate Performance and Cyclic Stability for Flexible Lithium‐Ion Batteries

A sulfur‐linked carbonyl‐based poly(2,5‐dihydroxyl‐1,4‐benzoquinonyl sulfide) (PDHBQS) compound is synthesized and used as cathode material for lithium‐ion batteries (LIBs). Flexible binder‐free composite cathode with single‐wall carbon nanotubes (PDHBQS–SWCNTs) is then fabricated through vacuum filtration method with SWCNTs. Electrochemical measurements show that PDHBQS–SWCNTs cathode can deliver a discharge capacity of 182 mA h g⁻¹ (0.9 mA h cm⁻²) at a current rate of 50 mA g⁻¹ and a potential window of 1.5 V–3.5 V. The cathode delivers a capacity of 75 mA h g⁻¹ (0.47 mA h cm⁻²) at 5000 mA g⁻¹, which confirms its good rate performance at high current density. PDHBQS–SWCNTs flexible cathode retains 89% of its initial capacity at 250 mA g⁻¹ after 500 charge–discharge cycles. Furthermore, large‐area (28 cm²) flexible batteries based on PDHBQS–SWCNTs cathode and lithium foils anode are also assembled. The flexible battery shows good electrochemical activities with continuous bending, which retains 88% of its initial discharge capacity after 2000 bending cycles. The significant capacity, high rate performance, superior cyclic performance, and good flexibility make this material a promising candidate for a future application of flexible LIBs.     

Stable bismuth-antimony alloy cathode with a conversion-dissolution/deposition mechanism for high-performance zinc batteries

Although a large number of intercalation cathode materials for aqueous Zn batteries have been reported, limited intercalation capacity precludes achieving a higher energy density. Here we develop a high-performance aqueous Zn battery based on BiSb alloy (Bi_0.5Sb_0.5) using a high-concentrated strong-basic polyelectrolyte. We demonstrate that a conversion-dissolution/deposition electrochemical mechanism (BiSb ↔ Bi + SbO₂⁻ ↔ Bi + SbO₃⁻ ↔ Bi₂O₃) through in situ X-ray diffraction (XRD), Raman, and ex-situ X-ray photoelectron spectrometry (XPS) characterizations with the help of density functional theory calculations. The BiSb cathode delivers large capacity of 512 mAh g⁻¹ at 0.3 Ag⁻¹ and superior rate capability of 90 mAh g⁻¹ even at 20 Ag⁻¹, and long-term cyclability with capacity retentions of 184 mAh g⁻¹ after 600 cycles at 0.5 Ag⁻¹ and 130 mAh g⁻¹ after 1300 cycles at 1 Ag⁻¹. Remarkably, even at temperatures as low as −10 and −20 °C, capacities of 210 and 197 mAh g⁻¹ are reserved at 1 Ag⁻¹, respectively. Moreover, the prepared pouch Zn//BiSb battery delivers a high energy density of 303 Wh kg⁻¹_BiSb at 0.3 Ag⁻¹. When coupled with a high concentration polyelectrolyte, the Zn/BiSb battery exhibits an excellent performance over a wide temperature range (−40 to 40 °C). Our research reveals the metal cathode is promising for Zn batteries to achieve a high performance with the unique mechanism and alloys can be an effective approach to stabilize metal electrodes for cycling.     

Bottom-Up Design of a Green and Transient Zinc-Ion Battery with Ultralong Lifespan

Transient batteries are expected to lessen the inherent environmental impact of traditional batteries that rely on toxic and critical raw materials. This work presents the bottom-up design of a fully transient Zn-ion battery (ZIB) made of nontoxic and earth-abundant elements, including a novel hydrogel electrolyte prepared by cross-linking agarose and carboxymethyl cellulose. Facilitated by a high ionic conductivity and a high positive zinc-ion species transference number, the optimized hydrogel electrolyte enables stable cycling of the Zn anode with a lifespan extending over 8500 h for 0.25 mA cm⁻² – 0.25 mAh cm⁻². On pairing with a biocompatible organic polydopamine-based cathode, the full cell ZIB delivers a capacity of 196 mAh g⁻¹ after 1000 cycles at a current density of 0.5 A g⁻¹ and a capacity of 110 mAh g⁻¹ after 10 000 cycles at a current density of 1 A g⁻¹. A transient ZIB with a biodegradable agarose casing displays an open circuit voltage of 1.123 V and provides a specific capacity of 157 mAh g⁻¹ after 200 cycles at a current density of 50 mA g⁻¹. After completing its service life, the battery can disintegrate under composting conditions.     

Highly Safe Electrolyte Enabled via Controllable Polysulfide Release and Efficient Conversion for Advanced Lithium–Sulfur Batteries

Conventional lithium–sulfur batteries often suffer from fatal problems such as high flammability, polysulfide shuttling, and lithium dendrites growth. Here, highly‐safe lithium–sulfur batteries based on flame‐retardant electrolyte (dimethoxyether/1,1,2,2‐tetrafluoroethyl 2,2,3,3‐tetrafluoropropyl ether) coupled with functional separator (nanoconductive carbon‐coated cellulose nonwoven) to resolve aforementioned bottle‐neck issues are demonstrated. It is found that this flame‐retardant electrolyte exhibits excellent flame retardancy and low solubility of polysulfide. In addition, Li/Li symmetrical cells using such flame‐retardant electrolyte deliver extraordinary long‐term cycling stability (less than 10 mV overpotential) for over 2500 h at 1.0 mA cm^?2 and 1.0 mAh cm^?2. Moreover, bare sulfur cathode–based lithium–sulfur batteries using this flame retardant electrolyte coupled with nanoconductive carbon‐coated cellulose separator can retain 83.6% discharge capacity after 200 cycles at 0.5 C. Under high charge/discharge rate (4 C), lithium–sulfur cells still show high charge/discharge capacity of ≈350 mAh g^?1. Even at an elevated temperature of 60 °C, discharge capacity of 870 mAh g^?1 can be retained. More importantly, high‐loading bare sulfur cathode (4 mg cm^?2)–based lithium–sulfur batteries can also deliver high charge/discharge capacity over 806 mAh g^?1 after 56 cycles. Undoubtedly, the strategy of flame retardant electrolyte coupled with carbon‐coated separator enlightens highly safe lithium–sulfur batteries at a wide range of temperature.     

3D Printing of a V8C7–VO2 Bifunctional Scaffold as an Effective Polysulfide Immobilizer and Lithium Stabilizer for Li–S Batteries

Lithium–sulfur (Li–S) batteries have heretofore attracted tremendous interest due to low cost and high energy density. In this realm, both the severe shuttling of polysulfide and the uncontrollable growth of dendritic lithium have greatly hindered their commercial viability. Recent years have witnessed the rapid development of rational approaches to simultaneously regulate polysulfide behaviors and restrain lithium dendritic growth. Nevertheless, the major obstacles for high-performance Li–S batteries still lie in little knowledge of bifunctional material candidates and inadequate explorations of advanced technologies for customizable devices. Herein, a “two-in-one” strategy is put forward to elaborate V₈C₇–VO₂ heterostructure scaffolds via the 3D printing (3DP) technique as dual-effective polysulfide immobilizer and lithium dendrite inhibitor for Li–S batteries. A thus-derived 3DP-V₈C₇–VO₂/S electrode demostrates excellent rate capability (643.5 mAh g⁻¹ at 6.0 C) and favorable cycling stability (a capacity decay of 0.061% per cycle at 4.0 C after 900 cycles). Importantly, the integrated Li–S battery harnessing both 3DP hosts realizes high areal capacity under high sulfur loadings (7.36 mAh cm⁻² at a sulfur loading of 9.2 mg cm⁻²). This work offers insight into solving the concurrent challenges for both S cathode and Li anode throughout 3DP.     

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.     

Initiating Hexagonal MoO3 for Superb-Stable and Fast NH4+ Storage Based on Hydrogen Bond Chemistry

Nonmetallic ammonium (NH₄⁺) ions are applied as charge carriers for aqueous batteries, where hexagonal MoO₃ is initially investigated as an anode candidate for NH₄⁺ storage. From experimental and first-principle calculated results, the battery chemistry proceeds with reversible building–breaking behaviors of hydrogen bonds between NH₄⁺ and tunneled MoO₃ electrode frameworks, where the ammoniation/deammoniation mechanism is dominated by nondiffusion-controlled pseudocapacitive behavior. Outstanding electrochemical performance of MoO₃ for NH₄⁺ storage is delivered with 115 mAh g⁻¹ at 1 C and can retain 32 mAh g⁻¹ at 150 C. Furthermore, it remarkably exhibits ultralong and stable cyclic performance up to 100 000 cycle with 94% capacity retention and high power density of 4170 W kg⁻¹ at 150 C. When coupled with CuFe prussian blue analogous (PBA) cathode, the full ammonium battery can deliver decent energy density 21.3 Wh kg⁻¹ and the resultant flexible ammonium batteries at device level are also pioneeringly developed for potential realistic applications.     

Coordinating Interface Polymerization with Micelle Mediated Assembly Towards Two-Dimensional Mesoporous Carbon/CoNi for Advanced Lithium–Sulfur Battery

Lithium-sulfur battery has attracted significant attention by virtues of their high theoretical energy density, natural abundance, and environmental friendliness. However, the notorious shuttle effect of polysulfides intermediates severely hinders its practical application. Herein, a novel 2D mesoporous N-doped carbon nanosheet with confined bimetallic CoNi nanoparticles sandwiched graphene (mNC-CoNi@rGO) is successfully fabricated through a coordinating interface polymerization and micelle mediated co-assembly strategy. mNC-CoNi@rGO serves as a robust host material that endows lithium-sulfur batteries with a high reversible capacity of 1115 mAh g⁻¹ at 0.2 C after 100 cycles, superior rate capability, and excellent cycling stability with 679.2 mAh g⁻¹ capacity retention over 700 cycles at 1 C. With sulfur contents of up to 5.0 mg cm⁻², the area capacity remains to be 5.1 mAh cm⁻² after 100 cycles at 0.2 C. The remarkable performance is further resolved via a series of experimental characterizations combined with density functional theory calculations. These results reveal that the ordered mesoporous N-doped carbon-encapsulated graphene framework acts as the ion/electron transport highway with excellent electrical conductivity, while bimetallic CoNi nanoparticles enhance the polysulfides adsorption and catalytic conversion that simultaneously accelerate the multiphase sulfur/polysulfides/sulfides conversion and inhibit the polysulfides shuttle.     

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.     

Nanoscale Borate Coating Network Stabilized Iron Oxide Anode for High-Energy-Density Bipolar Lithium-Ion Batteries

High-capacity metal oxides based on non-toxic earth-abundant elements offer unique opportunities as advanced anodes for lithium-ion batteries (LIBs). But they often suffer from large volumetric expansion, particle pulverization, extensive side reactions, and fast degradations during cycling. Here, an easy synthesis method is reported to construct amorphous borate coating network, which stabilizes conversion-type iron oxide anode for the high-energy-density semi-solid-state bipolar LIBs. The nano-borate coated iron oxide anode has high tap density (1.6 g cm⁻³), high capacity (710 mAh g⁻¹ between 0.5 – 3.0 V, vs Li/Li⁺), good rate performance (200 mAh g⁻¹ at 50 C), and excellent cycling stability (≈100% capacity resention over 1,000 cycles at 5 A g⁻¹). When paired with high-voltage cathode LiCoO₂, it enables Cu current collector-free pouch-type classic and bipolar full cells with high voltage (7.6 V with two stack layers), achieving high energy density (≈350 Wh kg⁻¹), outstanding power density (≈6,700 W kg⁻¹), and extended cycle life (75% capacity retention after 2,000 cycles at 2 C), superior to the state-of-the-art high-power LIBs using Li₄Ti₅O₁₂ anode. The design and methodology of the nanoscale polyanion-like coating can be applied to other metal oxides electrode materials, as well as other electrochemical materials and devices.     

Weak-Coordination Electrolyte Enabling Fast Li+ Transport in Lithium Metal Batteries at Ultra-Low Temperature

Lithium metal batteries (LMBs) are promising for next-generation high-energy-density batteries owing to the highest specific capacity and the lowest potential of Li metal anode. However, the LMBs are normally confronted with drastic capacity fading under extremely cold conditions mainly due to the freezing issue and sluggish Li⁺ desolvation process in commercial ethylene carbonate (EC)-based electrolyte at ultra-low temperature (e.g., below −30 °C). To overcome the above challenges, an anti-freezing carboxylic ester of methyl propionate (MP)-based electrolyte with weak Li⁺ coordination and low-freezing temperature (below −60 °C) is designed, and the corresponding LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) cathode exhibits a higher discharge capacity of 84.2 mAh g⁻¹ and energy density of 195.0 Wh kg⁻¹_cathode than that of the cathode (1.6 mAh g⁻¹ and 3.9 Wh kg⁻¹_cathode) working in commercial EC-based electrolytes for NCM811‖ Li cell at −60 °C. Molecular dynamics simulation, Raman spectra, and nuclear magnetic resonance characterizations reveal that rich mobile Li⁺ and the unique solvation structure with weak Li⁺ coordination are achieved in MP-based electrolyte, which collectively facilitate the Li⁺ transference process at low temperature. This work provides fundamental insights into low-temperature electrolytes by regulating solvation structure, and offers the basic guidelines for the design of low-temperature electrolytes for LMBs.     

S,N-codoped carbon capsules with microsized entrance: Highly stable S reservoir for Li-S batteries

Nanostructured carbon materials are extensively applied as host materials to improve the utilization rate and reversibility of elemental sulfur in lithium sulfur (Li-S) batteries. Here, S, N-codoped carbon capsules (SNCCs) with microporous walls, prepared by a self-assembly process, are used as the sulfur host material in Li-S batteries. The SNCCs provide plenty of micron-sized cavities to accommodate a high S loading, which are sealed by thick walls with microsized entrance to efficently suppress the shuttle effect of lithium polysulfides. As the cathode in Li-S battery, the SNCCs/sulfur composite with a sulfur mass loading of 70 wt% exhibits a high average reversible capacity of 1220 and 1116 mA h g^?1 at 0.5C and 1C, respectively, superior rate performance (905 and 605 mAh g^?1 at 5C and 10C, respectively) and excellent cycling stability (capacity fading rate of 0.03% per cycle in 500 cycles). Even at a high sulfur areal loading of 7.3 mg/cm², the SNCCs/0.7S electrode still deliver a high initial discharge capacity of 838 mAh g^?1 and keeps at 730 mAh g^?1 after 100 cycles, corresponding to an extraordinary capacity retention of 87.1%, showing an excellent cyclic stability. The outstanding electrochemical performance is associated with the unique capsule structure with abundant volume, microsized entrance and high conductivity. Our results provides a new strategy to prepare highly stable sulfur-carbon composites for the application in Li-S batteries.     

A Dual-Functional Conductive Framework Embedded with TiN-VN Heterostructures for Highly Efficient Polysulfide and Lithium Regulation toward Stable Li–S Full Batteries

Lithium–sulfur (Li–S) batteries are strongly considered as next-generation energy storage systems because of their high energy density. However, the shuttling of lithium polysulfides (LiPS), sluggish reaction kinetics, and uncontrollable Li-dendrite growth severely degrade the electrochemical performance of Li–S batteries. Herein, a dual-functional flexible free-standing carbon nanofiber conductive framework in situ embedded with TiN-VN heterostructures (TiN-VN@CNFs) as an advanced host simultaneously for both the sulfur cathode (S/TiN-VN@CNFs) and the lithium anode (Li/TiN-VN@CNFs) is designed. As cathode host, the TiN-VN@CNFs can offer synergistic function of physical confinement, chemical anchoring, and superb electrocatalysis of LiPS redox reactions. Meanwhile, the well-designed host with excellent lithiophilic feature can realize homogeneous lithium deposition for suppressing dendrite growth. Combined with these merits, the full battery (denoted as S/TiN-VN@CNFs || Li/TiN-VN@CNFs) exhibits remarkable electrochemical properties including high reversible capacity of 1110 mAh g⁻¹ after 100 cycles at 0.2 C and ultralong cycle life over 600 cycles at 2 C. Even with a high sulfur loading of 5.6 mg cm⁻², the full cell can achieve a high areal capacity of 5.5 mAh cm⁻² at 0.1 C. This work paves a new design from theoretical and experimental aspects for fabricating high-energy-density flexible Li–S full batteries.     

High Cathode Loading and Low-Temperature Operating Garnet-Based All-Solid-State Lithium Batteries – Material/Process/Architecture Optimization and Understanding of Cell Failure

All-solid-state lithium batteries (ASSLBs) are prepared using garnet-type solid electrolytes by quick liquid phase sintering (Q-LPS) without applying high pressure during the sintering. The cathode layers are quickly sintered with a heating rate of 50–100 K min⁻¹ and a dwell time of 10 min. The battery performance is dramatically improved by simultaneously optimizing materials, processes, and architectures, and the initial discharge capacity of the cell with a LiCoO₂-loading of 8.1 mg reaches 1 mAh cm⁻² and 130 mAh g⁻¹ at 25 °C. The all-solid-state cell exhibits capacity at a reduced temperature (10 °C) or a relatively high rate (0.1 C) compared to the previous reports. The Q-LPS would be suitable for large-scale manufacturing of ASSLBs. The multiphysics analyses indicate that the internal stress reaches 1 GPa during charge/discharge, which would induce several mechanical failures of the cells: broken electron networks, broken ion networks, separation of interfaces, and delamination of layers. The experimental results also support these failures.     

Defect-Rich Single Atom Catalyst Enhanced Polysulfide Conversion Kinetics to Upgrade Performance of Li–S Batteries

Lithium–sulfur (Li–S) batteries have attracted considerable attention owing to their extremely high energy densities. However, the application of Li–S batteries has been limited by low sulfur utilization, poor cycle stability, and low rate capability. Accelerating the rapid transformation of polysulfides is an effective approach for addressing these obstacles. In this study, a defect-rich single-atom catalytic material (Fe-N4/DCS) is designed. The abundantly defective environment is favorable for the uniform dispersion and stable existence of single-atom Fe, which not only improves the utilization of single-atom Fe but also efficiently adsorbs polysulfides and catalyzes the rapid transformation of polysulfides. To fully exploit the catalytic activity, catalytic materials are used to modify the routine separator (Fe-N₄/DCS/PP). Density functional theory and in situ Raman spectroscopy are used to demonstrate that Fe-N₄/DCS can effectively inhibit the shuttling of polysulfides and accelerate the redox reaction. Consequently, the Li–S battery with the modified separator achieves an ultralong cycle life (a capacity decay rate of only 0.03% per cycle at a current of 2 C after 800 cycles), and an excellent rate capability (894 mAh g⁻¹ at 3 C). Even at a high sulfur loading of 5.51 mg cm⁻² at 0.2 C, the reversible areal capacity still reaches 5.4 mAh cm⁻².     

Aqueous Zinc–Tellurium Batteries with Ultraflat Discharge Plateau and High Volumetric Capacity

Traditional aqueous zinc-ion batteries (ZIBs) based on ion-intercalation or surface redox behaviors at the cathode side suffer severely from an unsatisfactory specific capacity and unstable output potential. Herein, these issues are applied to a conversion-type zinc–tellurium (Zn–Te) battery. Typically, this battery works based on a two-step solid-to-solid conversion with the successive formation of zinc ditelluride (ZnTe₂) and zinc telluride (ZnTe). It delivers an ultrahigh volumetric capacity of 2619 mAh cm⁻³ (419 mAh g⁻¹), 74.1% of which is from the first conversion (Te to ZnTe₂) with an ultraflat discharge plateau. Though reported first in a challenging aqueous environment, this Zn–Te battery demonstrates an excellent capacity retention of >82.8% after 500 cycles, which results from the elimination of the notorious “shuttle effect” due to the solid-to-solid conversion behaviors. In addition, a quasi-solid-state Zn–Te battery is also fabricated, exhibiting superior flexibility, robustness, and good electrochemical performance. This work develops a novel cathode material based on conversion-type ion-storage mechanism. The system is attractive due to its ultrastable energy output, which is rarely reported for ZIBs.