A fast ionic transport copolymeric network for stable quasi-solid lithium metal battery

Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the uncontrollable solvents in solid electrolytes usually aggravate poor interfacial contact with lithium metal anode and deteriorate Li^(+) pathways.Here a copolymeric network-structured ion conductor by rationally integrating cellulose nanofibril as a two-in-one functional material is employed to anchor the solvent.Taking advantages of tightly anchoring of cellulose nanofibril to solvent,the asconstructed quasi-solid polymer-based electrolyte offers rapid Li^(+) transport channels and realizes effective Li-dendrite suppression,which enables high ionic conductivity of 1.93 × 10^(-3)S cm^(-1) at room temperature,long-term Li plating/stripping over 1900 h,and high capacity retention of 99%.This work provides a fresh strategy for creating solid electrolytes that meet both high ionic conductivity and interfacial stability requirements for practical solid-state lithium metal battery.

A bifunctional ethylene-vinyl acetate copolymer protective layer for dendrites-free lithium metal anodes

Lithium metal batteries are strongly considered as one of the most promising candidates for nextgeneration high-performance battery systems.However,the uncontrollable growth of lithium dendrites and the highly reactive lithium metal result in the severe safety risks and the short lifespan for highenergy-density rechargeable batteries.Here,we demonstrate a hydrophobic and ionically conductive ethylene-vinyl acetate(EVA)copolymer layer can not only endow lithium metal anodes with an air-stable and anti-water surface,but also efficiently suppress the lithium-dendrites growth during the electrochemical cycling process.Therefore,the introduction of the EVA copolymer as a bifunctional protection layer simultaneously improves the anti-water/air performance and electrochemical cycling stability of lithium metal anode.

Architecture engineering of carbonaceous anodes for high-rate potassium-ion batteries

The limited lithium resource in earth's crust has stimulated the pursuit of alternative energy storage technologies to lithium-ion battery.Potassium-ion batteries(KIBs)are regarded as a kind of promising candidate for large-scale energy storage owing to the high abundance and low cost of potassium resources.Nevertheless,further development and wide application of KIBs are still challenged by several obstacles,one of which is their fast capacity deterioration at high rates.A considerable amount of effort has recently been devoted to address this problem by developing advanced carbonaceous anode materials with diverse structures and morphologies.This review presents and highlights how the architecture engineering of carbonaceous anode materials gives rise to high-rate performances for KIBs,and also the beneficial conceptions are consciously extracted from the recent progress.Particularly,basic insights into the recent engineering strategies,structural innovation,and the related advances of carbonaceous anodes for high-rate KIBs are under specific concerns.Based on the achievements attained so far,a perspective on the foregoing,and proposed possible directions,and avenues for designing high-rate anodes,are presented finally.

Unveiling the role of lithiophilic sites denseness in regulating lithium ion deposition

The construction of lithiophilic sites is an effective way to achieve uniform lithium(Li)ion deposition for stably cycling Li metal batteries.However,in-depth investigations involving lithiophilic sites denseness(LSD)in impacting Li ion deposition remain unknown.Herein we propose an insight into this issue by probing the effect of LSD on determining the Li ion deposition.Experimental characterization and theoretical simulation demonstrate that rational LSD plays a vital role in both Li nucleation and the subsequent Li ion plating behaviors.By tailoring the LSD from low to high,the accompanied Li nucleation overpotentials continuously decrease.Additionally,the Li ion mobility increases first and then weakens in the subsequent Li ion plating stage.Consequently,the Li metal with a moderate LSD allows a dendritefree morphology and satisfactory long-term cycling performances.This work affords a deeper fundamental understanding of lithiophilic chemistry that directs the development of efficient strategies to realize dendrite-free Li metal batteries.

Synthesis of novel hierarchical porous polymers with a nanowire-interconnected network structure from core-shell polymer nanoobjects

Design and fabrication of the micro/nanostructures of the network units is a critical issue for porous nanonetwork structured materials. Significant progress has been attained in construction of the network units with zero-dimensional spherical shapes.However, owing to the limitations of synthetic methods, construction of porous building blocks in one dimension featuring high aspect ratios for porous nanonetwork structured polymer(PNSP) remains largely unexplored. Here we present the successful design and preparation of PNSP with a novel type of one-dimensional network unit, i.e., microporous heterogeneous nanowire. Well-defined core-shell polymer nanoobjects prepared from a gelable block copolymer, poly(3-(triethoxysilyl)propyl methacrylate)-block-polystyrene are employed as building blocks, and facilely transformed into PNSP via hypercrosslinking of polystyrene shell. The as-prepared PNSP exhibits unique three-dimensional hierarchical nanonetwork morphologies with large surface area. These findings could provide a new avenue for fabrication of unique well-defined PNSP, and thus generate valuable breakthroughs in many applications.

A review of rechargeable batteries for portable electronic devices

Portable electronic devices(PEDs)are promising information-exchange platforms for real-time responses.Their performance is becoming more and more sensitive to energy consumption.Rechargeable batteries are the primary energy source of PEDs and hold the key to guarantee their desired performance stability.With the remarkable progress in battery technologies,multifunctional PEDs have constantly been emerging to meet the requests of our daily life conveniently.The ongoing surge in demand for high-performance PEDs inspires the relentless pursuit of even more powerful rechargeable battery systems in turn.In this review,we present how battery technologies contribute to the fast rise of PEDs in the last decades.First,a comprehensive overview of historical advances in PEDs is outlined.Next,four types of representative rechargeable batteries and their impacts on the practical development of PEDs are described comprehensively.The development trends toward a new generation of batteries and the future research focuses are also presented.

Integrated lithium metal anode protected by composite solid electrolyte film enables stable quasi-solid-state lithium metal batteries

Lithium(Li) metal,possessing an extremely high theoretical specific capacity(3860 mAh/g) and the most negative electrode potential(-3.040 V vs.standard hydrogen electrode),is one the most favorable anode materials for future high-energy-density batteries.However,the poor cyclability and safety issues induced by extremely unstable interfaces of traditional liquid Li metal batteries have limited their practical applications.Herein,a quasi-solid battery is constructed to offer superior interfacial stability as well as excellent interfacial contact by the incorporation of Li@composite solid electrolyte integrated electrode and a limited amount of liquid electrolyte(7.5 μL/cm2).By combining the inorganic garnet Aldoped Li6.75La3Zr1.75Ta0.25O12(LLZO) with high mechanical strength and ionic conductivity and the o rganic ethylene-vinyl acetate copolymer(EVA) with good flexibility,the composite solid electrolyte film could provide sufficient ion channels,sustained interfacial contact and good mechanical stability at the anode side,which significantly alleviates the thermodynamic corrosion and safety problems induced by liquid electrolytes.This innovative and facile quasi-solid strategy is aimed to promote the intrinsic safety and stability of working Li metal anode,shedding light on the development of next-generation highperformance Li metal batteries.

交联封装实现高效的水稳定锂金属负极

锂金属被认为是开发下一代高比能电池负极的终极选择.然而,由于金属锂固有的高化学反应活性而导致的低湿空气耐受性以及不稳定的固体电解质界面(SEI),严重阻碍了锂金属负极的商业化应用.本文通过温度调控路易斯碱性环境下PVDF–HFP膜的交联,成功实现了锂金属负极的高效封装.得益于交联PVDF–HFP内在的疏水性以及致密的微结构,封装的锂负极表现出显著改善的水稳定性,在潮湿的空气(25°C, 30%RH)以及纯水条件下的耐受性得到了显著提升.此外,由于强极性PVDF–HFP聚合物对有机电解液的优异亲和力,封装后的锂金属负极在对称电池和全电池中均表现出更优的电化学性能.这项工作展示了一种对湿敏性碱金属电极新颖而有效的封装策略,旨在为基于碱金属的高能量密度电池的大规模、低成本应用铺平道路.