钠离子电池用铁基正极材料的研究进展

气候变化和化石燃料枯竭等问题将促进新型绿色能源的开发和利用。因此,高效率、低成本、安全的储能系统,得到了越来越多的关注和研究。在各类储能系统中,二次电池是存储电能、为电子设备供电的最理想选择。目前,锂离子电池(LIBs)的应用最广泛。然而,地球上锂资源的短缺和分布不均造成的成本较高,急需研究和开发其他高性能的新型二次电池。钠元素具有地壳中储量丰富、均匀且与锂具有相似化学性质等优势,使得钠离子电池(SIBs)成为了取代LIBs最有前景的备选二次电池之一。然而,钠离子的体积较大、离子传导动力学更缓慢、导电性更差等问题,限制了SIBs高性能的实现,这是目前研究的难点和重点。此外,铁具有储量丰富、环境友好的特点,其在SIBs中的应用引起了电池领域科研工作者的广泛关注。因此,寻找良好的铁基正极材料成为SIBs高性能电极材料开发的一个重要研究方向。本综述对近年来SIBs铁基正极材料方面的研究进展进行了总结,并按照聚阴离子型化合物、过渡金属氧化物、普鲁士蓝及类似物和氟化物分类,进行了系统的阐述和分析。     

NASICON结构正极材料用于钠离子电池的研究进展

随着二次电池技术的迅速发展,锂离子电池(LIBs)已经成为了当今社会一种重要的储能装置。然而,地壳中锂资源有限、含锂化合物价格昂贵,因此科研工作者正在积极寻找LIBs的替代品。钠离子电池(SIBs)具有与LIBs相似的工作原理,且钠元素在地球上储量更丰富更均匀、价格更低廉,使得SIBs成为了最有希望替代LIBs的新型二次电池体系之一。不过,钠离子半径较大、充放电过程中电极材料的不可逆性更明显等缺点,明显地增加了开发高性能SIBs的难度。因此,寻找具有优异性能的电极材料,成为了当前SIBs研究的难点和重点。钠超离子导体(NASICON)结构材料是一类具有超快钠离子传导能力的化合物,在脱/嵌钠过程中具有离子传导率高、结构稳定等优点,表现出明显的应用潜力。本文将在介绍NASICON材料晶体结构的基础上,重点从过渡金属种类与个数,以及阴离子调控的角度,总结其研究进展,并分析了该类材料面临的主要问题和挑战。     

钠离子电池关键材料研究及应用进展

钠离子资源丰富,分布广泛,价格低廉,因而钠离子电池被认为是下一代大规模储能技术的理想选择之一. 然而,钠离子较大的半径和质量不利于它与电极材料的可逆反应. 开发能够快速、稳定储钠的基质材料是提升钠离子电池性能的关键之一. 此外,如何合理地优化电解质,匹配正负极材料,以实现高性能、高安全、低成本钠离子全电池的构建,切实将其推向市场,也是亟待解决的问题. 本文综述了国内外钠离子电池关键材料（包括正极材料、负极材料和电解质）的研究进展,介绍了一些具有代表性的钠离子全电池实例. 对钠离子电池的基础研究和实际应用具有一定参考价值和借鉴意义.     

基于一体化正极与电解质膜的高性能固态电池

Lithium ion batteries (LIBs) are becoming the most popular energy storage systems in our society. However, frequently occurring accidents of electrical cars powered by LIBs have caused increased safety concern regarding LIBs. Solid-state lithium batteries (SSLBs) are believed to be the most promising next generation energy storage system due to their better in-built safety mechanisms than LIBs using flammable organic liquid electrolyte. However, constructing the ionic conducting path in SSLBs is challenging due to the slow ionic diffusion of Li ion in solid-state electrolyte, particularly in the case of solid-solid contact between the solid materials. In this paper, we demonstrate the construction of an integrated electrolyte and cathode for use in SSLBs. An integrated electrolyte and cathode membrane is obtained via simultaneous electrospinning and electrospraying of a polyacrylonitrile (PAN) electrolyte and a LiFePO₄ (LFP) cathode material respectively, for the cathode layer, followed by the electrospinning of PAN to prepare the electrolyte layer. The resultant integrated PAN-LFP membrane is flexible. Scanning electron microscopy and energy dispersive X-ray spectroscopy measurement results show that the electrode and electrolyte are in close contact with each other. After the integrated PAN-LFP membrane is filled with a succinonitrile-bistrifluoromethanesulfonimide (SN-LiTFSI) salt mixture, it is paired with a lithium foil metal anode electrode, and the resultant solid-state Li|PAN-LFP cell exhibits limited polarization and outstanding interfacial stability during long term cycling. That is, the Li|PAN-LFP cell presents a specific capacity of 160.8 mAh∙g⁻¹ at 0.1C, and 81% of the initial capacity is maintained after 500 cycles at 0.2C. The solid-state Li|PAN-LFP cell also exhibits excellent resilience in destructive tests such as cell bending and cutting.     

Regulation of Cathode‐Electrolyte Interphase via Electrolyte Additives in Lithium Ion Batteries

As the power supply of the prosperous new energy products, advanced lithium ion batteries (LIBs) are widely applied to portable energy equipment and large‐scale energy storage systems. To broaden the applicable range, considerable endeavours have been devoted towards improving the energy and power density of LIBs. However, the side reaction caused by the close contact between the electrode (particularly the cathode) and the electrolyte leads to capacity decay and structural degradation, which is a tricky problem to be solved. In order to overcome this obstacle, the researchers focused their attention on electrolyte additives. By adding additives to the electrolyte, the construction of a stable cathode‐electrolyte interphase (CEI) between the cathode and the electrolyte has been proven to competently elevate the overall electrochemical performance of LIBs. However, how to choose electrolyte additives that match different cathode systems ideally to achieve stable CEI layer construction and high‐performance LIBs is still in the stage of repeated experiments and exploration. This article specifically introduces the working mechanism of diverse electrolyte additives for forming a stable CEI layer and summarizes the latest research progress in the application of electrolyte additives for LIBs with diverse cathode materials. Finally, we tentatively set forth recommendations on the screening and customization of ideal additives required for the construction of robust CEI layer in LIBs. We believe this minireview will have a certain reference value for the design and construction of stable CEI layer to realize desirable performance of LIBs.     

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.     

Recent Advances in Aerosol‐Assisted Spray Processes for the Design and Fabrication of Nanostructured Metal Chalcogenides for Sodium‐Ion Batteries

Increasing demand for sodium‐ion batteries (SIBs), one of the most feasible alternatives to lithium ion batteries (LIBs), has resulted because of their high energy density, low cost, and excellent cycling stability. Consequently, the design and fabrication of suitable electrode materials that govern the overall performance of SIBs are important. Aerosol‐assisted spray processes have gained recent prominence as feasible, scalable, and cost‐effective methods for preparing electrode materials. Herein, recent advances in aerosol‐assisted spray processes for the fabrication of nanostructured metal chalcogenides (e.g., metal sulfides, selenides, and tellurides) for SIBs, with a focus on improving the electrochemical performance of metal chalcogenides, are summarized. Finally, the improvements, limitations, and direction of future research into aerosol‐assisted spray processes for the fabrication of various electrode materials are presented.     

一种新型的碳复合钼掺杂的钒氧化物纳米线钠离子电池正极材料

近年来,由于锂资源逐渐紧缺而导致其成本增加,锂离子电池发展受到了限制. 作为一个有潜力的替代者,有着相似电化学机制且成本较低的钠离子电池则发展迅速. 但由于钠离子与锂离子相较有着更大半径,在钠离子脱嵌过程中,对大多数电极材料的晶体结构破坏严重. 因此,开发新型电极材料对钠离子电池的进一步发展尤为重要. 其中,层状钒氧化物作为正极材料被广泛研究. 在这项工作中,作者基于钒氧化物,引入钼元素并与碳复合,首次设计合成了一种新型的碳复合钼掺杂的钒氧化物纳米线电极材料,并获得了优良的电化学性能（在50 mA•g^-1的电流密度下,最高放电比容量达135.9 mAh•g^-1,并在循环75次后仍有82.6mAh•g^-1的可逆容量,容量保持率高达71.8%;在1000mA•g^-1的高电流密度下循环并回到50mA•g^-1后,可逆放电比容量仍能回复至111.5mAh•g^-1）. 本工作的研究结果证明,这种具有超大层间距的新型碳复合钼掺杂的钒氧化物纳米线是一种非常有潜力的储钠材料,并且我们的工作为钠离子电池的进一步发展提供了一定的理论基础.     

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.     

不可燃氟代碳酸酯基钠离子电池电解液

Lithium-ion batteries (LIBs) are widely used in cellphones, laptops, and electric cars owing to their high energy density and long operational lifetime. However, their further deployment in large-scale energy storage systems is restricted by the uneven distribution of lithium resources (~0.0017% (mass fraction, w) in the Earth's crust). Therefore, alternative energy storage systems composed of abundant elements are of urgent need. Recently, sodium-ion batteries (SIBs) have attracted significant attention and are considered to be a potential alternative for next-generation batteries owing to abundant sodium resources (~2.64% (w) of the Earth's crust), suitable potential (−2.71 V), and low cost. SIBs are similar to LIBs in terms of their physical and electrochemical properties. Previous studies have mainly focused on SIB storage materials, including hard carbon, alloys, and hexacyanoferrate, while the safety of SIBs remains largely unexplored. Similar to LIBs, the current electrolytes used in SIBs are mainly composed of flammable organic carbonate solvents (or ether solvents), sodium salts, and functional additives, which pose possible safety issues. Moreover, the chemical activity of sodium is much higher than that of lithium, leading to a higher risk of fire, thermal runaway, and explosion. To overcome this problem, herein we propose a fluorinated non-flammable electrolyte composed of 0.9 mol∙L⁻¹ NaPF₆ (sodium hexafluorophosphate) in an intermixture of di-(2, 2, 2 trifluoroethyl) carbonate (TFEC) and fluoroethylene carbonate (FEC) in a 7 : 3 ratio by volume. Its physical and electrochemical properties were studied by ionic conductivity, direct ignition, cyclic voltammetry, and charge/discharge measurements, demonstrating excellent flame-retarding ability and outstanding compatibility with sodium electrodes. The electrochemical tests showed that the Prussian blue cathode retained a capacity of 84 mAh∙g⁻¹ over 50 cycles in the prepared electrolyte, in contrast to the rapid capacity degradation in a flammable conventional carbonate electrolyte (74 mAh∙g⁻¹ with 57% capacity retention after 50 cycles). To test the practical application of the proposed electrolyte, a hard carbon anode was used and exhibited exceptional performance in this system. The enhancement mechanism was further verified by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning emission microscopy (SEM) investigations. Polycarbonate on the surface of the cathode played an important role for the studied electrolyte system. The polycarbonate may originate from FEC decomposition, which can enhance the ionic conductivity of the solid electrolyte interface (SEI) layer and reduce impedance. Hence, we believe that this proposed electrolyte may provide new opportunities for the design of robust and safe SIBs for next-generation applications.     

高比能钠离子电池预钠化技术研究进展

钠离子电池有望取代锂离子电池实现大规模储能应用。然而,储钠负极材料具有较低的初始库伦效率,制约了高比能钠离子电池的开发。预钠化技术被认为是补偿负极活性钠损失、提升电池能量密度的最直接有效的方法,对于钠离子电池的商业化应用具有重要意义。本文全面总结近年来预钠化技术的最新研究进展,包括短接法预钠化、电化学预钠化、钠金属物理预钠化、化学预钠化和正极补钠添加剂等,并从反应原理、安全性、可操作性、处理效率和可放大性等角度分析讨论现有各技术方案的优势及面临的挑战;着重介绍化学预钠化和正极补钠添加剂,这两类最具应用前景的预钠化技术的最新成果,进而从实用化角度深入探讨仍待解决的科学问题和技术难点。本文可为预钠化技术的进一步优化和高比能钠离子电池的开发提供思路。     

From Solid‐Solution Electrodes and the Rocking‐Chair Concept to Today's Batteries

Lithium‐ion batteries (LIBs) have become ubiquitous power sources for small electronic devices, electric vehicles, and stationary energy storage systems. Despite the success of LIBs which is acknowledged by their increasing commodity market, the historical evolution of the chemistry behind the LIB technologies is laden with obstacles and yet to be unambiguously documented. This Viewpoint outlines chronologically the most essential findings related to today's LIBs, including commercial electrode and electrolyte materials, but furthermore also depicts how the today popular and widely emerging solid‐state batteries were instrumental at very early stages in the development of LIBs.     

A Biodegradable Polydopamine‐Derived Electrode Material for High‐Capacity and Long‐Life Lithium‐Ion and Sodium‐Ion Batteries

Polydopamine (PDA), which is biodegradable and is derived from naturally occurring products, can be employed as an electrode material, wherein controllable partial oxidization plays a key role in balancing the proportion of redox‐active carbonyl groups and the structural stability and conductivity. Unexpectedly, the optimized PDA derivative endows lithium‐ion batteries (LIBs) or sodium‐ion batteries (SIBs) with superior electrochemical performances, including high capacities (1818 mAh g^?1 for LIBs and 500 mAh g^?1 for SIBs) and good stable cyclabilities (93 % capacity retention after 580 cycles for LIBs; 100 % capacity retention after 1024 cycles for SIBs), which are much better than those of their counterparts with conventional binders.     

锂电池电极过程的原位电化学原子力显微镜研究进展

随着人类对能源的使用与存储需求不断增加,高能量密度和高安全性能的二次锂电池体系正在被不断地开发与完善.深入理解充放电过程中锂电池内部电极/电解质界面的电化学过程以及微观反应机理,有利于指导电池材料的优化设计.原位电化学原子力显微镜将原子力显微镜的高分辨表界面分析优势与电化学反应装置相结合,能够在电池运行条件下实现对电极/电解质界面的原位可视化研究,并进一步从纳米尺度上揭示界面结构的演化规律与动力学过程.本文总结了原位电化学原子力显微镜在锂电池电极过程中的最新研究进展,主要包括基于转化型反应的正极过程、固体电解质中间相的动态演化以及固态电池界面演化与失效分析.     

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.     

基于聚碳酸丙烯酯基聚合物电解质和有机正极的全固态钠电池

Sodium-ion batteries (SIBs) are promising candidates to replace lithium-ion batteries (LIBs) to meet the emergent requirements of various commercial applications. SIBs and LIBs are similar in many aspects, including their reduction potentials, approximate energy densities, and ionic semidiameters. Analogously, safety issues, including liquid leakage, high flammability, and explosiveness limit the usage of SIBs. All-solid-state batteries have the potential to solve the aforementioned problems. However, polycarbonates as promising solid electrolytes have been rarely exploited in all-solid-state SIBs. In addition, organic electrode materials, including non-conjugated redox polymers, carbonyl compounds, organosulfur compounds, and layered compounds, have been intensively investigated as part of various energy storage systems owing to their low cost, environmental friendliness, high energy density, and structural diversity. Nevertheless, the dissolution of small organic compounds in organic-liquid electrolytes has hindered its further applications. Fortunately, the utilization of solid polymer electrolytes combined with organic electrode materials is a promising method to prevent dissolution into the electrolyte and improve the cycling performance of SIBs. Thus, we proposed the utilization of a poly(propylene carbonate) (PPC)-based solid polymer electrolyte and cellulose nonwoven with a 3, 4, 9, 10-perylene-tetracarboxylicacid-dianhydride (PTCDA) cathode in an all-solid-state sodium battery (ASSS). The solid electrolyte significantly enhanced the safety of the SIB and was successfully synthesized via a facile method. The morphology of the as-prepared solid electrolyte was examined by electron scanning microscopy (SEM). Furthermore, the electrochemical performances of the PTCDA/Na battery with organic-liquid and solid electrolytes at room temperature were compared. The SEM results demonstrated that the solid polymer electrolyte and sodium bis(fluorosulfonyl)imide (NaFSI) were evenly distributed inside the pores of the nonwoven cellulose. The ionic conductivity of the composite solid polymer electrolyte (CSPE) at room temperature was 3.01 × 10^-5 S·cm^-1, suggesting that the CSPE was a promising candidate for commercial applications. In addition, the ASSS showed significantly improved cycling performance at a current density of 50 mAh·g^-1 with a high capacity retention of 99.1%, whereas the discharge capacity of the liquid PTCDA/Na battery was only 24.6mAh·g^-1 after 50 cycles. This indicated that the cycling performance of the PTCDA cathode in the SIB was largely improved by preventing the dissolution of the PTCDA cathode material in the electrolyte. Electrochemical impedance spectroscopy results demonstrated that the CSPE was compatible with the organic cathode electrode.     

A Truxenone-based Covalent Organic Framework as an All-Solid-State Lithium-Ion Battery Cathode with High Capacity

All-solid-state lithium ion batteries (LIBs) are ideal for energy storage given their safety and long-term stability. However, there is a limited availability of viable electrode active materials. Herein, we report a truxenone-based covalent organic framework (COF-TRO) as cathode materials for all-solid-state LIBs. The high-density carbonyl groups combined with the ordered crystalline COF structure greatly facilitate lithium ion storage via reversible redox reactions. As a result, a high specific capacity of 268 mAh g⁻¹, almost 97.5 % of the calculated theoretical capacity was achieved. To the best of our knowledge, this is the highest capacity among all COF-based cathode materials for all-solid-state LIBs reported so far. Moreover, the excellent cycling stability (99.9 % capacity retention after 100 cycles at 0.1 C rate) shown by COF-TRO suggests such truxenone-based COFs have great potential in energy storage applications.     

A review on electrode and electrolyte for lithium ion batteries under low temperature

Under low temperature (LT) conditions (−80 °C∼0 °C), lithium-ion batteries (LIBs) may experience the formation of an extensive solid electrolyte interface (SEI), which can cause a series of detrimental effects such as Li⁺ deposition and irregular dendritic filament growth on the electrolyte surface. These issues ultimately lead to the degradation of the LT performance of LIBs. As a result, new electrode/electrolyte materials are necessary to address these challenges and enable the proper functioning of LIBs at LT. Given that most electrochemical reactions in lithium-ion batteries occur at the electrode/electrolyte interface, finding solutions to mitigate the negative impact caused by SEI is crucial to improve the LT performance of LIBs. In this article, we analyze and summarize the recent studies on electrode and electrolyte materials for low temperature lithium-ion batteries (LIBs). These materials include both metallic materials like tin, manganese, and cobalt, as well as non-metallic materials such as graphite and graphene. Modified materials, such as those with nano or alloying characteristics, generally exhibit better properties than raw materials. For instance, Sn nanowire-Si nanoparticles (SiNPs−In-SnNWs) and tin dioxide carbon nanotubes (SnO₂@CNT) have faster Li⁺ transport rates and higher reversible capacity at LT. However, it′s important to note that when operating under LT, the electrolyte may solidify, leading to difficulty in Li⁺ transmission. The compatibility between the electrolyte and electrode can affect the formation of the solid electrolyte interphase (SEI) and the stability of the electrode/electrolyte system. Therefore, a good electrode/electrolyte system is crucial for successful operation of LIBs at LT.     

Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium‐Ion Batteries

Sodium‐ion batteries (SIBs) are regarded as an attractive alternative to lithium‐ion batteries (LIBs) for large‐scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g^?1 after 100 cycles at 100 mA g^?1. The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g^?1 are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g^?1, respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres.