Synergistic effect of lithiophilic Zn nanoparticles and N-doping for stable Li metal anodes

Li metal is the most ideal anode material for next-generation high energy lithium-ion batteries.The uncontrollable growth of Li dendrites,however,hinders its practical application.Herein,we propose the adoption of Zn nanoparticles uniformly embedded in N-doped carbon polyhedra homogeneously built on carbon cloth(Zn@NC@CC)to prevent the formation of Li dendrites.Based on theoretical calculation and experimental observation,lithiophilic Zn nanoparticles and N-doping inside of the assynthesized Zn@NC play a synergistic role in enhancing the adsorption capacity with Li,thus resulting in uniform Li deposition and complete suppression of Li dendrites.Moreover,the porous N-doped carbon polyhedras uniformly distributed on carbon cloth effectively relieves the volume change of Li upon repeated Li stripping/plating process,which contributes to preserving the structural integrity of the whole electrode and hence enhancing its long-term cycling stability.Benefiting from these synergistic effects,the Li-Zn@NC@CC electrode delivers a prolonged lifespan of over 1200 h at 1 mA cm^(-2) with an areal capacity of 1 mA h cm^(-2) in symmetric cells and high Coulombic efficiencies of 95.4%under an ultrahigh capacity of 12 mA h cm^(-2).Remarkably,Li-Zn@NC@CC//LiFePO_(4) full cells deliver a high reversible capacity of 110.2 mA h g^(-1) at 1 C over 200 cycles.

Boosting lifespan of conversion-reaction anodes for full/half potassium-ion batteries via multi-dimensional carbon nano-architectures confinement effect

Transition metal selenides are regarded as prospective conversion-reaction anodes for potassium-ion batteries(PIBs)because of their relatively high electrical conductivity,large theoretical specific capacity,abundant resources and low cost.The challenge of the metal selenides originates from a serious volume change during cycling,which induces serious structural collapse and fast capacity degradation.In the present work,the multi-dimensional carbon nano-architectures confined bimetallic selenides(ZnSe/CoSe_(2)@N-CNTs/rGO)were constructed by a facile MOF-assisted strategy.In such special nanoarchitectures,N-doped CNTs protect the metal selenides centers from serious volume expansion/electrode pulverization,as well as improve the sluggish kinetics.ZnSe/CoSe_(2)@N-CNTs/rGO electrode boosts the lifespan of half PIBs with a large discharge specific capacity of 200 m Ah g^(-1)at 2 A g^(-1)after 3800 cycles.The full PIBs battery with ZnSe/CoSe_(2)@N-CNTs/rGO electrode as anode and Prussian blue as cathode exhibits well electrochemical performance(151 m Ah g^(-1)at 100 m A g^(-1)after 100 cycles).DFT calculation suggests that the CNTs could change the K+adsorption energy and decrease K+diffusion energy barrier,which dramatically enhances K+storage kinetics.This work offers an effective material engineering approach for designing hierarchical“all-in-one”electrodes with high excellent cycling stability for PIBs.

Addressing cation mixing in layered structured cathodes for lithium-ion batteries:A critical review

High-performance lithium-ion batteries(LIB)are important in powering emerging technologies.Cathodes are regarded as the bottleneck of increasing battery energy density,among which layered oxides are the most promising candidates for LIB.However,a limitation with layered oxides cathodes is the transition metal and Li site mixing,which significantly impacts battery capacity and cycling stability.Despite recent research on Li/Ni mixing,there is a lack of comprehensive understanding of the origin of cation mixing between the transition metal and Li;therefore,practical means to address it.Here,a critical review of cation mixing in layered cathodes has been provided,emphasising the understanding of cation mixing mechanisms and their impact on cathode material design.We list and compare advanced characterisation techniques to detect cation mixing in the material structure;examine methods to regulate the degree of cation mixing in layered oxides to boost battery capacity and cycling performance,and critically assess how these can be applied practically.An appraisal of future research directions,including superexchange interaction to stabilise structures and boost capacity retention has also been concluded.Findings will be of immediate benefit in the design of layered cathodes for high-performance rechargeable LIB and,therefore,of interest to researchers and manufacturers.

Prelithiation strategies for silicon-based anode in high energy density lithium-ion battery

Green energy storage devices play vital roles in reducing fossil fuel emissions and achieving carbon neutrality by 2050.Growing markets for portable electronics and electric vehicles create tremendous demand for advanced lithium-ion batteries(LIBs)with high power and energy density,and novel electrode material with high capacity and energy density is one of the keys to next-generation LIBs.Silicon-based materials,with high specific capacity,abundant natural resources,high-level safety and environmental friendliness,are quite promising alternative anode materials.However,significant volume expansion and redundant side reactions with electrolytes lead to active lithium loss and decreased coulombic efficiency(CE)of silicon-based material,which hinders the commercial application of silicon-based anode.Prelithiation,preembedding extra lithium ions in the electrodes,is a promising approach to replenish the lithium loss during cycling.Recent progress on prelithiation strategies for silicon-based anode,including electrochemical method,chemical method,direct contact method,and active material method,and their practical potentials are reviewed and prospected here.The development of advanced Si-based material and prelithiation technologies is expected to provide promising approaches for the large-scale application of silicon-based materials.

Recent progress in electrolyte design for advanced lithium metal batteries

Lithium metal batteries(LMBs)have attracted considerable interest for use in electric vehicles and as next-generation energy storage devices because of their high energy density.However,a significant practical drawback with LMBs is the instability of the Li metal/electrolyte interface,with concurrent parasitic reactions and dendrite growth,that leads to low Coulombic efficiency and poor cycle life.Owing to the significant role of electrolytes in batteries,rationally designed electrolytes can improve the electrochemical performance of LMBs and possibly achieve fast charge and a wide range of working temperatures to meet various requirements of the market in the future.Although there are some review papers about electrolytes for LMBs,the focus has been on a single parameter or single performance separately and,therefore,not sufficient for the design of electrolytes for advanced LMBs for a wide range of working environments.This review presents a systematic summary of recent progress made in terms of electrolytes,covering the fundamental understanding of the mechanism,scientific challenges,and strategies to address drawbacks of electrolytes for high-performance LMBs.The advantages and disadvantages of various electrolyte strategies are also analyzed,yielding suggestions for optimum properties of electrolytes for advanced LMBs applications.Finally,the most promising research directions for electrolytes are discussed briefly.

A critical review of ferritin as a drug nanocarrier:Structure,properties,comparative advantages and challenges

Ferritin stores and releases iron ions in mammals.It is globally important as a drug nanocarrier.This is because of its unique hollow-spherical structure,desirable stability and biological properties.Novel drug-loading approaches plus various functionalization approaches have been developed to improve ferritin in response to differing demands in disease treatments.Here,we critically review ferritin drug delivery and evaluate its diverse drug-loading and functionalization approaches,we:(1)Introduce basic structural and property information related to ferritin as a drug nanocarrier;(2)Contrast in detail the different means to load drugs and the selection of drug loading means;(3)Discuss multiple ferritin functionalization approaches,together with related advantages and potential risks;and,(4)Compare ferritin with alternative,commonly-used drug nanocarriers.We conclude that despite that no drugs based on ferritin are commercially available,the market potential for it is significant,and evaluate future research directions.Findings from this work will be of immediate benefit and interest to a wide range of researchers and manufacturers for drug delivery using ferritin.

Constructing ultrastable electrode/electrolyte interface for rapid potassium ion storage capability via salt chemistry and interfacial engineering

Conversion/alloying anode materials exhibiting high K storage capacities suffer from large volume variations and unstable electrode/electrolyte interfaces upon cycling.Herein,taking SnS/reduced graphene oxide(SnS/rGO)anodes as an example,the electrochemical performance of SnS/rGO could significantly be improved via employing potassium bis(fluorosulfonyl)imide(KFSI)salt in electrolytes and ultrathin TiO_(2) coating.KF-rich inorganic layer was demonstrated to help form robust SEI layer,which could suppress the side reactions to increase the Coulombic efficiency.The formed potassiated K_(x)TiO_(2) coating layer was constructed to boost charge transfer capability and K-ion diffusion kinetics.The as-prepared SnS/rGO@TiO_(2)-20 electrode in KFSI electrolyte delivers the high CE of 99.1%and 424 mAh·g^(−1) after 200 cycles with an ultrahigh capacity retention of 98.5%.

Understanding voltage hysteresis and decay during anionic redox reaction in layered transition metal oxide cathodes:A critical review

The emergence of anionic redox reactions in layered transition metal oxide cathodes provides practical opportunity to boost the energy density of rechargeable batteries.However,the activation of anionic redox reaction in layered oxides has significant voltage hysteresis and decay that reduce battery performance and limit commercialization.Here,we critically review the up-todate development of anionic redox reaction in layered oxide cathodes,summarize the proposed reaction mechanism,and unveil their connection to voltage hysteresis and decay based on the state-of-the-art progress.In addition,advances associated with various modification approaches to mitigate the voltage hysteresis/decay in layered transition metal oxide cathodes are also included.Finally,we conclude with an appraisal of further research directions including rational design of high-performance layered oxide cathodes with reversible anionic redox reactions and suppressed voltage hysteresis/decay.Findings will be of immediate benefit to the development of layered oxide cathodes for high performance rechargeable batteries.

Free-standing polymer-metal-organic framework membrane with high proton conductivity and water stability

As a new class of porous material,polymer-metal-organic framework(polyMOF)has attracted tremendous interests owing to their combined advantages of polymer and crystalline MOF.However,the poor film-forming ability of polyMOF limits its widespread application,especially in membrane separation area.Herein,for the first time,we demonstrate the fabrication of freestanding polyMOF membrane.The polyMOF nanosheets are synthesized by a polymer-assisted self-inhibition crystal growth strategy.Followed by self-assembly through vacuum filtration,a 20μm-thick free-standing polyMOF membrane is constructed.Benefiting from the inclusion of polymer with hydrophobic backbone and the continuously distributed non-coordinated hydrophilic groups along polymer chain,the polyMOF membrane attains excellent structure stability against water,as well as superior proton transfer property.Proton conductivity as high as 112 and 25.6 mS·cm^(–1)is obtained by this polyMOF membrane at 100%and 20%relative humidity(RH),respectively,which are two orders of magnitude higher than those of pristine MOF.The conductivity under low humidity(20%RH)is even over 8 times higher than that of commercial Nafion membrane(3 mS·cm^(–1)).This study may provide some guidance on the development of polyMOF membranes.