Recent Developments in Alloying‐type Anode Materials for Potassium‐Ion Batteries

As an energy‐storage system, rechargeable potassium‐ion batteries (PIBs) have aroused widespread attention in recent years due to their earth abundance, low standard redox potential, and high ionic conductivity. The development of high‐performance electrode materials is key to optimize the battery performance and useful to improve the feasibility of PIB technology. In this sense, a minireview on alloying‐type anode materials for advanced PIBs is provided, covering the potassium storage properties, reaction mechanisms, theoretical analysis, electrochemical performance, and suitable binders and electrolytes.     

锂硫银锗矿固态电解质研究进展

全固态电池因其较高的安全性和能量密度而成为下一代电动汽车和智能电网用储能器件的重点研究方向之一。开发具有高室温锂离子电导率、化学/电化学稳定性优异、对电极材料兼容性优异等特点的固态电解质材料是推动全固态电池发展的重要研究课题之一。硫化物电解质因其相对较高的室温电导率(~10⁻³ S∙cm⁻¹)、较低的电解质/电极固-固界面阻抗等优点而在众多无机固体电解质材料中成为研究热点。本文基于作者多年研究成果和当前国内外发表的相关工作,从电解质的结构、离子传导、合成、综合性能改善及在全固态电池中的应用等方面系统总结了锂硫银锗矿固态电解质材料研究,并分析了该类电解质面临的问题和挑战,最后探讨了其未来可能的研究方向和发展趋势。     

Synthesis Strategies and Applications for Pitch-Based Anode: From Industrial By-Products to Power Sources

It is significant for saving energy to manufacture superb-property batteries. Carbon is one of the most competitive anode materials in batteries, but it is hard for commercial graphite anodes to meet the increasingly higher energy-storage requirements. Moreover, the price of other better-performing carbon materials (such as graphene) is much higher than graphite, which is not conducive to massive production. Pitch, the cheap by-product in the petroleum and coal industries, has high carbon content and yield, making it possible for commercialization. Developing pitch-based anodes can not only lower raw material costs but also realize the pitch′s high value-added utilization. We comprehensively reviewed the latest synthesis strategies of pitch-derived materials and then introduced their application and research progress in lithium, sodium, and potassium ion batteries (LIBs, SIBs, and PIBs). Finally, we summarize and suggest the pitch′s development trend for anodes and in other fields.     

Progress of Prussian Blue and Its Analogues as Cathode Materials for Potassium Ion Batteries

Environmental pollution and the energy crisis have promoted the development of clean energy as well as new-generation energy storage systems. Potassium ion batteries (PIBs) have emerged as a possible alternative to lithium-ion batteries due to their abundant reserves, low cost, and impressive electrochemical performance. However, the search for suitable cathode materials has become particularly crucial. Recently, Prussian blue (PB) has been investigated as a potential cathode material for PIBs, which has an open three-dimensional framework to accommodate a large volume of potassium ions and adjustable composition for different applications. In this review, Prussian blue and its analogues (PBAs) and their application in PIBs were summarized detailly. We presented the composition, structure, potassium ion storage mechanism, preparation process of PBAs, and then focus on the performance optimization methods of the PBAs, including transition metal doping and conductive material adding into PBAs. Finally, the challenges as well as the outlook on the future development of PBAs were proposed for further application in this battery system.     

Developing better ester- and ether-based electrolytes for potassium-ion batteries

Potassium-ion batteries (PIBs) have attracted extensive attention for next-generation energy storage systems because of the high abundance of potassium resources and low cost. However, the electrochemical performance of PIBs still cannot satisfy the requirements of practical application. One of the most effective strategies to improve the electrochemical performance of PIBs is electrolyte optimization. In this review, we focus on recent advances in ester- and ether-based electrolytes for high-performance PIBs. First, we discuss the requirements and components of organic electrolytes (potassium salts and solvents) for PIBs. Then, the strategies toward optimizing the electrolytes have been summarized, including potassium salt optimization, solvent optimization, electrolyte concentration optimization, and introducing electrolyte additives. In general, the electrolyte optimization methods can adjust the solvation energy, the lowest unoccupied molecular orbital energy level, and the highest occupied molecular orbital energy level, which are beneficial for achieving fast kinetics, stable and highly K⁺-conductive solid-electrolyte interphase layer, and superior oxidation resistance, respectively. Future studies should focus on exploring the effects of composition on electrolyte characteristics and the corresponding laws. This review provides some significant guidance to develop better electrolytes for high-performance PIBs.

A comprehensive summary on how to optimize ester- and ether-based electrolytes for high-performance potassium-ion batteries.     

Constructing oxygen-deficient V2O3@C nanospheres for high performance potassium ion batteries

Potassium ion batteries (PIBs) have been regarded as promising alternatives to lithium ion batteries (LIBs) on account of their abundant resource and low cost in large scale energy storage applications. However, it still remains great challenges to explore suitable electrode materials that can reversibly accommodate large size of potassium ions. Here, we construct oxygen-deficient V₂O₃ nanoparticles encapsulated in amorphous carbon shell (O_d-V₂O₃@C) as anode materials for PIBs by subtly combining the strategies of morphology and deficiency engineering. The MOF derived nanostructure along with uniform carbon coating layer can not only enables fast K⁺ migration and charge transfer kinetics, but also accommodate volume change and maintain structural stability. Besides, the introduction of oxygen deficiency intrinsically tunes the electronic structure of materials according to DFT calculation, and thus lead to improved electrochemical performance. When utilized as anode for PIBs, O_d-V₂O₃@C electrode exhibits superior rate capability (reversible capacities of 262.8, 227.8, 201.5, 179.8, 156.9 mAh/g at 100, 200, 500, 1000 and 2000 mA/g, respectively), and ultralong cycle life (127.4 mAh/g after 1000 cycles at 2 A/g). This study demonstrates a feasible way to realize high performance PIBs through morphology and deficiency engineering.     

锂硫电池硫碳复合正极材料研究现状及展望

二次锂硫电池被视为最具有发展潜力的下一代高能量密度二次电池之一. 但由于正极硫的电导率低（5×10^-30 S·cm^-1）,且在放电过程中产生的中间体多硫化物易溶于有机电解液,致使锂硫电池活性物质利用率降低,溶解后的多硫化物还会迁移到负极,被还原成不溶物Li2S2/Li2S而沉积于负极锂,使电极结构遭受破坏,造成电池容量大幅衰减,循环性能差,从而限制了进一步的开发应用. 研究表明,以碳作为导电骨架的硫碳复合正极材料能在不同程度上解决上述问题,从而有效提高了锂硫电池的放电容量和循环性能. 本文综述了近年来国内外报道的各种锂硫电池正极材料的研究进展,结合作者课题组的研究,重点探讨了硫碳复合正极材料,并对其今后的发展趋势进行了展望.     

金属氧化物电化学电容器

电化学电容器是一类利用电化学双电层或电极材料在电极表面及体相发生的氧化还原反应而存储能量的装置，具有高比能量、良好的可逆性和长循环寿命。金属氧化物电极目前主要有贵金属氧化物和过渡金属氧化物。本文简要介绍了金属氧化物电化学电容器的储能机理、特点及应用，总结了电极材料的制备及改性方法；并简要评述了电极材料的研究进展。     

Electrochemical behavior of LiCoO2 as aqueous lithium-ion battery electrodes

Despite the large number of studies on the behavior of LiCoO₂ in organic electrolytes and its recent application as a positive electrode in rechargeable water battery prototypes, a little information is available about the lithium intercalation reaction in this layered compound in aqueous electrolytes. This work shows that LiCoO₂ electrodes can be reversibly cycled in LiNO₃ aqueous electrolytes for tens of cycles at remarkably high rates with impressive values specific capacity higher than 100 mAh/g, and with a coulomb efficiency greater than 99.7%. Stable and reproducible cycling measurements have been made using a simple cell design that can be easily applied to the study of other intercalation materials, assuming that they are stable in water and that their intercalation potential range matches the electrochemical stability window of the aqueous electrolyte. The experimental arrangement uses a three-electrode flooded cell in which another insertion compound acts as a reversible source and sink of lithium ions, i.e., as the counter electrode. A commercial reference electrode is also present. Both the working and the counter electrodes have been prepared as thin layers on a metallic substrate using the procedures typical for the study of electrodes for lithium-ion batteries in organic solvent electrolytes.     

Binder-free electrodes for advanced potassium-ion batteries:A review

Potassium-ion batteries(PIBs) have attracted enormous attention due to the abundance of potassium resources,low cost,fast ionic conductivity of electrolyte and relatively high operating voltage.Despite great effo rts and progress,researches on PIBs are still at the initial stage,especially in the emerging field of flexible and wearable PIBs.The inevitable challenges for PIBs include low reversible capacity,unsatisfactory cycling stability and insufficient energy density,the solution to which mostly relies on designing adva nced electrodes.Binder-free electrodes have emerged as promising electrode architecture for PIBs.Such electrodes avoid the use of insulating binders,which can be designed with various synergistic functional materials to address the aforementioned PIB issues and be endowed with flexibility/wearability.In this review,we mainly summarize the recent progress on binde r-free electrodes for PIBs,with the focus on the methodologies,detailed strategies and functional materials for electrode construction.One strategy for binder-free electrodes is to assemble free-standing architecture with the help of carbon nanotubes(CNTs),graphitic fibers,and other carbon or mechanically robust materials,either alone or in combination.The other effective strategy is current collector substrate-assisted direct growth,including the use of carbon cloth,metal.MXenes and other conductive substrates.Additionally,challenges and research opportunities are put forward at the end as the guidance for future development of binder-free PIB devices.     

卤化物固态电解质研究进展

全固态电池因其高能量密度和高安全性而成为具有发展前景的下一代储能技术。开发具有高室温离子电导率、优异化学/电化学稳定性、良好正/负极兼容性的固态电解质是实现全固态电池实用化的关键。卤化物固态电解质因其优异的电化学窗口、高正极稳定性、可接受的室温锂离子电导率等优势,受到了广泛的关注。本文通过对近年来卤化物电解质的相关研究进行总结,综述了该类电解质的组成、结构、离子传导路径及制备方法,并分析了金属卤化物电解质的电导率、稳定性特点,归纳了近年来该电解质在全固态电池中具有代表性的应用,并基于以上总结和分析,指出了卤化物固态电解质的研究难点及发展方向。     

钾离子电池负极的高性能潜在材料:锑

近年来随着对储能器件的需求增加,钾离子电池受到越来越多的关注.钾的物理化学性质与锂相似,且在地壳中的储量丰富,在储能领域中具有广阔的发展前景.但由于电极材料实际容量远小于理论容量等问题的存在导致应用在钾离子电池的性能仍有不足.金属锑(Sb)具有较高的理论容量被广泛应用在电极材料上,然而在充放电过程体积变化过大导致稳定性...     

拉曼光谱在锂离子电池研究中的应用

综述拉曼光谱(Raman spectroscopy)在锂离子电池碳负极材料、尖晶石LiMn2O4和LiFePO4正极材料、聚合物和室温熔盐电解质以及电极/电解质界面膜研究中的应用,分析了非原位拉曼测试手段与原位拉曼测试手段的优缺点,展望了这一领域目前有待解决的问题和可能应用的新技术.     

Advanced Carbon Materials for Non-aqueous Potassium Ion Battery Anodes

Owing to the abundant reserves and low cost, potassium ion batteries(PIBs), as potential alternatives to lithium ion batteries(LIBs) in the field of grid-level electrical energy storage systems, have triggered extensive research interest recently. Taking into consideration of the cost, environmental benignity and sustainability, carbon-based materials are supposed to be a promising choice for PIB anodes. In this perspective, we summarize the carbon-based materials with various microstructures toward PIBs and try to offer comprehensive understanding the underlying mechanism of potassium(K) ion storage. In addition, several strategies including heteroatom doping, morphology engineering, defect engineering, interlayer engineering, and composition engineering are proposed to rationally design the nanostructures of the advanced carbon-based PIB anodes. Finally, we conclude the current challenges and provide our perspectives on the development of high-performance carbon materials for PIB anodes.     

Uniform-dispersed ZnS quantum dots loading on graphene as a promising anode for potassium-ion batteries

The potassium-ion batteries(PIBs) have become the promising energy storage devices due to their relatively moderate cost and plenteous potassium resources.Whereas,the main drawback of PIBs is unsatisfacto ry electrochemical perfo rmance induced by the larger ionic radius of potassium ion.Herein,we report a well-designed,uniform-dispersed,and morphology-controllable zinc sulfide(ZnS) quantum dots loading on graphene as an anode in the PIBs.The directed uniform dispersion of the in-situ growing ZnS quantum dots(～2.8 nm in size) on graphene can mitigate the volume effect during the insertionextraction process and shorten the migration path of potassium ions.As a result,the battery exhibits superior cycling stability(350.4 mAh/g over 200 cycles at 0.1 A/g) and rate performance(98.8 mAh/g at2.0 A/g).We believe the design of active material with quantum dot-minimized size provides a novel route into PIBs and contributes to eliminating the major electrode failure issues of the system.     

First-principles calculations of stability of graphene-like BC_3 monolayer and its high-performance potassium storage

With increasing demand for renewable energy,graphene-like BC_3 monolayer as high performance electrode materials for lithium and sodium batteries are drawing more attention recently.However,its structural stability,potassium storage properties and strain effect on adsorption properties of alkali metal ions have not been reported yet.In this work,phonon spectra,AIMD simulations and elastic constants of graphene-like BC_3 monolayer are investigated.Our results show that graphene-like BC_3 monolayer possesses excellent structural stability and the maximum theoretical potassium storage capacity can reach up to 1653 mAh/g with the corresponding open circuit voltages 0.66 V.Due to potassium atom can be effectively adsorbed at the most energetically favorable h-CC site with obvious charge transfer,making adsorbed graphene-like BC_3 monolayer change from semiconductor to metal which is really good for electrode utilization.Moreover,the migrations potassium atom on the graphene-like BC_3 monolayer is rather fast with the diffusion barriers as low as 0.12 eV,comparing lithium atom with a relatively large diffusion barrier of 0.46 eV.Additionally,the tensile strains applied on the graphene-like BC_3 monolayer have marginal effect on the adsorption and diffusion performances of lithium,sodium and potassium atoms.     

金属锂电池的热失控与安全性研究进展

锂离子电池在便携式储能器件及电动汽车领域得到了广泛应用,然而频繁发生的电池起火爆炸事故,使热失控和热安全问题备受人们关注,目前已有多篇综述报道了缓解锂离子电池热失控的措施。相比于已经接近理论比能极限的锂离子电池,金属锂负极具有更高的比容量、更低的电势和高反应活性,但是不可控的锂枝晶生长,使得金属锂电池的热失控问题更为复杂和严重。针对金属锂电池的热失控问题,本文首先介绍了热失控的诱因及基本过程和阶段,其次从材料层面综述了提高电池热安全性的多种策略,包括使用阻燃性电解质、离子液体电解质、高浓电解质和局域高浓电解质等不易燃液态电解质体系,开发高热稳定性隔膜、热响应隔膜、阻燃性隔膜和具有枝晶检测预警与枝晶消除功能的新型智能隔膜,以及研究热响应聚合物电解质,最后对金属锂电池热失控在未来的进一步研究进行了展望。     

Antimony anchored in MoS2 nanosheets with N-doped carbon coating to boost potassium storage performance

Potassium ions batteries (PIBs) have been considered as promising energy storage systems owning to potassium rich natural abundances. However, the difficult reaction kinetics and poor cycling of electrode restrict the further development of PIBs. In this work, antimony anchored in MoS₂ nanosheets with N-doped carbon coating (Sb/MoS₂/NCs) are prepared and evaluated as anode for PIBs. In the unique Sb/MoS₂/NCs structure, the volume expansion of Sb particles could be effectively buffered by the around MoS₂ structure. The defects in MoS₂ nanosheets provide more electrochemical reaction sites for sufficient K⁺ insertion/extraction. Furthermore, the N-doped carbon can further accommodate the volume expansion and improve the electronic conductivity of Sb/MoS₂/NCs composites. Due to the above advantages, the Sb/MoS₂/NCs anode delivers a capacity of 235 mAh/g at 50 mA/g after 78 cycles. This work provides a prospective strategy to design advanced anode materials for PIBs using MoS₂ and antimony composites.     

聚合物水凝胶基超级电容器的研究进展

可伸展性和可压缩性是超级电容器作为现代柔性可穿戴电子设备的关键性能。聚合物水凝胶因其优异的力学性能、独特的网络状结构等优点,成为新一代高性能超级电容器的理想材料。它不仅可作为高效储能的柔性电极材料,而且可作为准固态电解质材料,在克服传统液体电解质系列缺陷的同时,获得更加轻薄、安全、稳定的柔性全固态储能器件。本文以聚合物水凝胶的化学组成为线索,分别介绍了聚合物水凝胶在超级电容器电极和电解质两方面的应用研究进展,并进一步对聚合物水凝胶在该领域的发展趋势进行了展望。     

Folic acid-based supramolecules for enhanced stability in potassium ion batteries

Organics present significant prospects as environmentally friendly and sustainable electrode materials for potassium ion batteries(PIBs) because of their abundant, recyclable and highly customizable characteristics. However, small molecular organics are easily solubilized in organic electrolytes, resulting in a low capacity and poor stability. Herein, the folic acid-based supermolecules(SM-FAs) are successfully prepared by a hydrothermal assisted self-assembly strategy. Due to multi-locus hydrog...