A Novel Coating-Extrusion Method Enabled, High Energy, Power Density, and Scalable Production in Monolithically Integrated Energy Storage Fibers.

The rise of wearable electronics demands flexible energy storage solutions like flexible fiber energy storage devices (FESDs), known for their flexibility and portability. However, it remains difficult for existing fabrication methods (typically, finite-coating, thermal-drawing, and solution-extrusion) to simultaneously achieve desirable electrochemical performances and fast production of FESDs. Here, a new scalable coating-extrusion method is developed, utilizing a novel extruded spinneret with tapered apertures to create dual pressure zones.

External Li supply reshapes Li deficiency and lifetime limit of batteries.

Lithium (Li) ions are central to the energy storing functionality of rechargeable batteries. Present technology relies on sophisticated Li-inclusive electrode materials to provide Li ions and exactingly protect them to ensure a decent lifetime. Li-deficient materials are thus excluded from battery design, and the battery fails when active Li ions are consumed.

Ultrathin and capacity-tunable lithium metal wires for lithium-based fiber batteries.

Ultrathin lithium (Li) metal wires with tunable capacities have great promise for precise prelithiation of fiber anodes and high-energy-density Li-based fiber batteries. However, the application of Li metal in fiber batteries faces great challenges due to its mechanical fragility and the resulting limited micro-dimension manufacturing capability. These challenges impede the production of ultrathin Li wires with adjustable Li contents to match the capacities of Li-based fiber batteries.

Robust Nanoscale Anode Protective Layers toward Fast-Charge High-Energy-Density Lithium Metal Batteries.

Mechanically stable and structurally homogeneous lithium-electrolyte interfacial layers are crucial in stabilizing lithium (Li) anodes for practical Li metal batteries. Herein, an ultrathin (≈84 nm) and robust artificial protective layer is constructed with reactive two-dimensional (2D) molecular brushes as building blocks. The artificial protective layer can in situ react with underlying Li metal to produce a nanoscale poly(lithium styrenesulfonate)-grafted graphene oxide (GO-g-PSSLi) layer on the outermost surface and an infinite Li-Ag solid solution in the anode.

Quasi-solid Fiber-shaped Lithium-ion Batteries with Fire Resistance.

Flexible batteries such as scalable fiber-shaped lithium-ion batteries (FLIBs) hold great potential for powering wearable electronics due to their excellent electrochemical performance, flexibility, and weavability. However, the use of organic liquid electrolytes raises serious safety concerns, including leakage and combustion hazards. In this study, we develop fire-resistant lithium cobalt oxide/graphite FLIBs by employing an in situ polymerized gel polymer electrolyte (GPE) incorporating 1,3,3,5,5-pentafluoro-1-ethoxy-cyclotriphosphazene (PFPN) as a flame retardant and triethylene glycol dimethacrylate (TEGDMA) as a crosslinker.

All-in-One Polymer Gel Electrolyte towards High-Efficiency and Stable Fiber Zinc-Air Battery.

Fiber zinc-air batteries are explored as promising power systems for wearable and portable electronic devices due to their intrinsic safety and the use of ambient oxygen as cathode material. However, challenges such as limited zinc anode reversibility and sluggish cathode reaction kinetics result in poor cycling stability and low energy efficiency. To address these challenges, we design a polydopamine-based all-in-one gel electrolyte (PAGE) that simultaneously regulates the reversibility of zinc anodes and the kinetics of air cathodes through polydopamine interfacial and redox chemistry, respectively.

Decreased Electrically and Increased Ionically Conducting Scaffolds for Long-Life, High-Rate and Deep-Capacity Lithium-Metal Anodes.

Lithium (Li) metal batteries are deemed as promising next-generation power solutions but are hindered by the uncontrolled dendrite growth and infinite volume change of Li anodes. The extensively studied 3D scaffolds as solutions generally lead to undesired "top-growth" of Li due to their high electrical conductivity and the lack of ion-transporting pathways. Here, by reducing electrical conductivity and increasing the ionic conductivity of the scaffold, the deposition spot of Li to the bottom of the scaffold can be regulated, thus resulting in a safe bottom-up plating mode of the Li and dendrite-free Li deposition.

Braided Fiber Current Collectors for High-Energy-Density Fiber Lithium-Ion Batteries.

Fiber lithium-ion batteries represent a promising power strategy for the rising wearable electronics. However, most fiber current collectors are solid with vastly increased weights of inactive materials and sluggish charge transport, thus resulting in low energy densities which have hindered the development of fiber lithium-ion batteries in the past decade. Here, a braided fiber current collector with multiple channels was prepared by multi-axial winding method to not only increase the mass fraction of active materials, but also to promote ion transport along fiber electrodes.

A robust all-organic protective layer towards ultrahigh-rate and large-capacity Li metal anodes.

The low cycling efficiency and uncontrolled dendrite growth resulting from an unstable and heterogeneous lithium-electrolyte interface have largely hindered the practical application of lithium metal batteries. In this study, a robust all-organic interfacial protective layer has been developed to achieve a highly efficient and dendrite-free lithium metal anode by the rational integration of porous polymer-based molecular brushes (poly(oligo(ethylene glycol) methyl ether methacrylate)-grafted, hypercrosslinked poly(4-chloromethylstyrene) nanospheres, denoted as xPCMS-g-PEGMA) with single-ion-conductive lithiated Nafion. The porous xPCMS inner cores with rigid hypercrosslinked skeletons substantially increase mechanical robustness and provide adequate channels for rapid ionic conduction, while the flexible PEGMA and lithiated Nafion polymers enable the formation of a structurally stable artificial protective layer with uniform Li diffusion and high Li transference number.

Boosting Cycling Stability and Rate Capability of Li-CO Batteries via Synergistic Photoelectric Effect and Plasmonic Interaction.

Sluggish CO reduction/evolution kinetics at cathodes seriously impede the realistic applications of Li-CO batteries. Herein, synergistic photoelectric effect and plasmonic interaction are introduced to accelerate CO reduction/evolution reactions by designing a silver nanoparticle-decorated titanium dioxide nanotube array cathode. The incident light excites energetic photoelectrons/holes in titanium dioxide to overcome reaction barriers, and induces the intensified electric field around silver nanoparticles to enable effective separation/transfer of photogenerated carriers and a thermodynamically favorable reaction pathway.

3D porous carbon networks with highly dispersed SiO by molecular-scale engineering toward stable lithium metal anodes.

3D porous carbon networks with highly dispersed SiOx have been successfully prepared by molecular-scale engineering with 1D molecular-brush precursors. Benefiting from the high-porosity interconnected structure and the lithiophilic SiOx nanodomains, the as-obtained composites show great advantages as 3D hosts to achieve stable Li plating/stripping.

Two-dimensional molecular brush-functionalized porous bilayer composite separators toward ultrastable high-current density lithium metal anodes.

Lithium metal batteries have been considerably limited by the problems of uncontrolled dendritic lithium formation and the highly reactive nature of lithium with electrolytes. Herein, we have developed functional porous bilayer composite separators by simply blade-coating polyacrylamide-grafted graphene oxide molecular brushes onto commercial polypropylene separators. Our functional porous bilayer composite separators integrate the lithiophilic feature of hairy polyacrylamide chains and fast electrolyte diffusion pathways with the excellent mechanical strength of graphene oxide nanosheets and thus enable molecular-level homogeneous and fast lithium ionic flux on the surfaces of electrodes.