水系锌二次电池MnO2正极的晶体结构、反应机理及其改性策略

Because of the advantages of high safety, environment-friendliness, affordability, and ease of processing, aqueous rechargeable zinc batteries (ARZBs) are promising candidates for next-generation large-scale energy storage systems. In recent years, various cathode materials based on vanadium/manganese/cobalt oxides, Prussian blue analogs, and organic compounds have been reported. Among them, manganese dioxide (MnO₂) is widely used in ARZBs due to their outstanding advantages of low toxicity, eco-friendliness, and high capacity (616 mAh∙g⁻¹ based on two-electron transfer). However, the diversity of the crystal structures of MnO₂ and the unpredictability of the electrochemical reaction make it difficult to investigate the specific internal storage mechanism, which impedes further development of the optimal modification strategies. To date, the main recognized energy storage mechanisms are (de)intercalation and dissolution-deposition mechanisms. In the traditional (de)intercalation mechanism, the predominant issues related to MnO₂ during the cycling process include Mn dissolution, irreversible phase transformation, structural collapse, and sluggish ion diffusion kinetics. On the other hand, the detailed reaction path for the dissolution-deposition mechanism, which was developed in recent years, remains controversial. In addition, the incomplete dissolution-deposition of MnO₂ and the highly acidic environment inevitably leads to corrosion and hydrogen evolution of the zinc anode, as well as low Coulombic efficiency. Accordingly, optimization strategies for different reaction mechanisms have been proposed to make zinc-manganese batteries more competitive. For the (de)intercalation mechanism, modification of composite materials and nanostructure optimization strategies can be adopted to inhibit the dissolution of MnO₂ and increase the number of highly active reaction sites, thus enhancing the electrochemical performance. Moreover, the guest pre-intercalation strategy can help optimize the crystal structure of MnO₂, preventing the collapse of the internal structure during cycling. Besides, defect engineering and element doping strategies focus on regulating the distribution of the electronic structure for affecting the properties of MnO₂, resulting in lowering the energy barrier of zinc insertion. For the dissolution-deposition mechanism, the introduction of a neutral acetate and a halide mediator can effectively facilitate the dissolution-deposition of MnO₂. Meanwhile, metal element catalysis can accelerate the reaction kinetics of the MnO₂ dissolution-deposition, so that high-rate performance can be achieved. Furthermore, the decoupling battery system can separate the cathodic and anodic electrolytes to restrain the hydrogen and oxygen evolution reactions and enhance the potential difference. The flow battery system can effectively eliminate the influence of concentration polarization and stabilize the ion concentration in the electrolytes, thus leading to a large capacity (> 100 mAh). Undoubtedly, MnO₂ as a high-capacity, high-voltage cathode material has broad development prospects for ARZBs. Here, we systematically summarize the crystal structures and reaction mechanisms of MnO₂. We also discuss the optimization strategies toward advanced MnO₂ cathode materials for resolving the highlighted issues in zinc-manganese batteries, which are expected to provide research directions for the design and development of high-performance ARZBs.      

高电压水系二次电池设计新策略

受水的分解电压(1.23 V)所限,水系二次电池的开路电压普遍不高。本文在分析水系二次电池开路电压影响因素的基础上,介绍了目前提高开路电压的几种新策略,并分别讨论其优缺点。     

高稳定性水系锌离子电池正极材料MnO2@MgO的制备与性能

采用共沉淀法和热分解法合成了具有核壳结构的MnO2@MgO微球。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等手段对材料进行表征,结果发现包覆MgO不改变MnO2的结构,包覆层由纳米颗粒组成,厚度约为50 nm。电化学性能结果显示,包覆后材料的放电比容量明显提高,在100 mA·g^-1电流密度下,最大放电比容量为274.3 mAh·g^-1,比未包覆材料提高了12.8%。在1000 mA·g^-1电流密度下经过500次循环后,包覆后材料的放电比容量保持率高达84.1%,表现出优异的循环稳定性。MgO包覆层的存在避免了MnO2与电解液之间直接接触,抑制了电极材料在充放电过程中锰的溶解,从而显著提高MnO2的循环性能。     

电解液对水系可充电池MnO2正极电化学性能的影响

研究了水系电解液中Li⁺、Zn²⁺和Mn²⁺阳离子对具有不同晶型结构和形貌的MnO₂正极电化学性能的影响,探讨其储能机理。结果表明,在不含Mn(II)离子的水溶液中,MnO₂电极所表现的电化学性能趋同,容量低,衰减快。含有Zn²⁺离子的水溶液中,MnO₂电极因二价锌离子的嵌入-脱出,容量明显提升,但衰减严重。当溶液中同时含有Zn²⁺、Mn²⁺离子时,基于Mn²⁺和Zn²⁺离子之间的协同作用和Mn²⁺离子氧化/还原反应过程的作用,有效抑制MnO₂颗粒的聚集和结构塌陷,削弱碱式硫酸锌杂质不利的影响,保持了锌离子在MnO₂电极中嵌入-脱出的高容量特性(200 mAh·g^-1,电流密度：100 mA·g^-1),及良好的循环稳定性。     

水系锌离子电池锌负极保护策略

水系锌离子电池采用金属锌作为负极材料,具有绿色环保、安全等优势,有望用于大规模储能。锌金属的储量比锂更加丰富,也更容易开采与提纯。同时,锌具有较低的氧化还原电位(-0.76V vs SHE)和较高的理论比容量(820 mAh·g^-1)和体积容量密度(5 854 mAh·cm^-3)。由于充放电过程中存在锌枝晶和不可逆副产物(如H₂、ZnO、Zn₄(OH)₆SO₄)等问题,造成锌负极的库仑效率较低,严重缩短了电池的循环寿命,限制了其实际应用。本文针对锌负极在实际应用中遇到的困难与瓶颈,从微观层面分析了锌负极沉积/溶解的动力学与热力学机理,并从锌电极表面改性、锌片内部结构优化、电解液改性和新型隔膜等方面,介绍了锌负极保护的各种策略,并通过具体实例,分析了其制备方法和改性机理以及最终对电池性能的改善效果,为实用高效的锌负极保护方法提供了思路。最后,文章讨论了锌负极在商业化过程中面临的机遇和挑战,并对未来的研究前景和热点进行了展望。     

非水介质中Zn—MnO2的可充性研究

报道了以尖晶石型二氧化猛为正极，１ｍｏｌ／Ｌ＾－１Ｚｎ（ＣｌＯ４）２的碳酸丙烯酯为电解液构成Ｚｎ－ＭｎＯ２二次电池体系的充放电性质和反应机理分析。结果表明，这一体系的充放电过程表现为Ｚｎ在λ－ＭｎＯ２中的电化学嵌入和脱嵌反应。     

水系锌离子电池锰基正极材料

水系锌离子电池(AZIBs)以低成本、高安全性和高环保特性在大规模储能领域具有广阔的应用前景,当前备受关注的正极材料是研究的热点.锰基化合物因具有资源丰富、环境友好和价格低廉等优点,是最具市场应用前景的一类正极材料.本文详细综述了不同锰基化合物的结构特点以及锰基AZIBs在充放电过程中涉及的四种储能机理,讨论了AZIB...     

锌离子在水相介南Zn／V2O5二次电池中的迁移性能研究

利用间歇性恒电流测定法和Ｘ－Ｒａｙ衍射法，研究水相介质的Ｚｎ／Ｖ２Ｏ５二次电池中的锌离子在正材料中的迁移性能及其放电机理；讨论锌离子正极材料中发生迁移时的某些动力学参数与放电深度的关系，实验结果表明，该电池的正极放电反应为锌离子在ＺｎｘＶ２Ｏ５中的嵌入过程。     

水系锌离子电池宽温域性能的电解质改性策略研究进展

在资源短缺、能源需求倍增的当今世界,水系锌离子电池（AZIBs）作为一种大规模储能技术以其具有高安全性、低成本、高容量和快速充放电等优势脱颖而出。随着对能源多元化应用场景的增加,AZIBs被开发并应用于多种极端环境。然而,电池中的自由水分子会引发一系列的不良反应,导致电池出现容量下降和寿命缩短的问题。在低温条件下,溶剂水的冻结会引起AZIBs的离子电导率降低、电荷转移阻抗增加,导致电池速率性能下降。在高温条件下,溶剂水的快速蒸发会产生气泡和气体膨胀,水诱导的副反应加剧,同时电极材料也会出现腐蚀和溶解,从而影响电池寿命。针对这些挑战,在这篇综述中,分别总结了针对水系锌离子电池在高温与低温下的研究进展,提出了适用于低温、高温以及同时适用于高低温的电解质策略,重点研究了高浓度电解质、凝胶电解质、电解质添加剂和共晶电解质降低电解质凝固点、提高低温电化学性能的机理,并对进一步提高水系锌离子电池的宽温域性能和工业应用进行了展望。     

非水系二次锂-氧电池正极

非水系二次锂-氧电池(NRLOB)在当前所研发的二次电池中理论能量密度最高,但存在循环性能差,充、放电电流密度低等显著问题;这些问题主要同其氧正极上的电化学反应相关,关键在于过氧化锂Li₂O₂可逆生成、分解反应能否在较高的速率下连续地进行。本文综述了近年来NRLOB正极电化学反应机理、正极碳材料、催化剂和电极结构、电解液分解导致电极副反应等方面的研究现状;归纳了今后需要进一步研究的主要问题。     

聚吡咯@二氧化锰/碳纳米管薄膜电极的制备及在高性能锌离子电池中的应用

中性/弱酸性水系锌锰电池因其能量密度高、价格低廉、环境友好等优势受到广泛关注。然而,现有的二氧化锰正极材料存在导电性能差,在充放电过程中易于溶解等问题。这严重影响了电池的倍率性能和循环稳定性,阻碍了中性锌锰电池的应用。为了解决上述问题,本文设计了以碳纳米管(CNT)网络薄膜为导电基底沉积聚吡咯(PPy)包覆二氧化锰(PPy@MnO₂/CNT)的多级结构电极。碳纳米管和聚吡咯组装形成高比表面积的三维交联导电网络,为活性材料提供了快速的电子、离子传输通道;聚吡咯包覆纳米级二氧化锰能够有效地抑制二氧化锰的溶解,进而提升电池的倍率特性和循环稳定性。以PPy@MnO₂/CNT作为正极材料组装的水系锌锰电池在1 A·g^-1的电流密度下,比容量达到210 mAh·g^-1,循环1000圈后,电池依然具有较高的容量保持率(85.7%)。本工作的导电聚合物包覆活性物质的策略可为发展高稳定柔性储能器件提供新思路。     

钠离子电池用高性能锑基负极材料的调控策略研究进展

锑(Sb)具有高的理论比容量、较小的电极极化、合适的Na⁺脱嵌电位、价格低廉以及环境友好的优势,而成为一种具有较大应用前景的钠离子电池负极材料。但是,Sb基负极材料的一个重要挑战是在循环过程中高比容量伴随着大的体积变化,进而导致活性材料粉化,并从集流体上脱落,这大大限制了其在钠离子电池领域的大规模应用。因此,如何解决Sb基负极材料充放电过程中体积膨胀问题对于高性能的钠离子电池设计是至关重要的。本文详细综述和讨论了Sb基材料的结构-性能关系及其在钠离子电池中的应用,详细介绍了钠离子电池Sb基负极材料在氧化还原反应机理、形貌设计、结构-性能关系等方面的最新研究进展。本综述的主要目的是探讨影响Sb基负极材料性能的决定因素,从而提出有前途的改性策略,以提高其可逆容量和循环稳定性。最后,对Sb基钠离子电池负极材料的未来发展、面临的挑战和前景进行了展望。本文可为Sb负极材料的构建和优化提供具体的观点,阐明了Sb基负极材料未来的发展方向,从而促进钠离子电池的快速发展和实际应用。     

钠离子电池用高性能锑基负极材料的调控策略研究进展

Na-ion batteries (SIBs) are promising alternatives for Li-ion batteries owing to the natural abundance of sodium resources and similar energy storage mechanisms. Although significant progress has been achieved in research on SIBs, there remain several challenges to be addressed. One of the major challenges in the construction of high-performance SIBs is the development of suitable anode materials with a large reversible capacity, high cycling stability, and good rate performance. Alloying anode materials mainly composed of elements from Groups IVA and VA, as well as their alloys, have attracted widespread attention because of their low working voltage, high cost-effectiveness, and large theoretical capacity. Alloying-type anode materials can be alloyed with metallic Na to achieve large reversible capacities, ensuring a high energy density. Antimony is a promising anode material for SIBs owing to its high theoretical specific capacity (660 mAh·g⁻¹, corresponding to the full sodiation Na₃Sb alloy), small degree of electrode polarization (~0.25 V), appropriate Na⁺ deintercalation potential (0.5–0.75 V), low price, and environmental friendliness. However, an important challenge for using Sb-based anode materials is that the high specific capacity is accompanied by large volume changes during cycling. Such changes lead to the pulverization of the active materials and their falling off from the collector, which significantly limit their large-scale application in the field of sodium-ion batteries. Therefore, mitigating the volume expansion issue of Sb-based anode materials in the charge-discharge process is very important for the design of high-performance SIBs. In recent years, researchers have attempted to address this issue by designing special structures to prepare various composites, and substantial progress has been achieved in improving the electrochemical performance of SIBs. In this review, the relationship between the structure and properties of Sb-based materials and their applications in SIBs are presented and discussed in detail. The latest research progress on using Sb-based anode materials for SIBs in redox reaction mechanisms along with their morphology design, structure-performance relationship, etc. have been reviewed. The main objective of this review is to explore the determining factors of the performance of Sb-based anode materials to propose suitable modification strategies for improving their reversible capacity and cycle stability. Finally, future developments, challenges, and prospects of Sb-based anode materials for SIBs are discussed. Despite several challenges, Sb-based materials are very promising anode materials for SIBs with alloying reaction mechanisms. To further improve the large-scale application of Sb-based anode materials, it is necessary to optimize the binder, electrode structure, and electrolyte composition. The combination of in-depth studies on the electrochemical reaction mechanisms and advanced characterization technologies is important for the development and construction of advanced Sb-based anode materials for SIBs. Finally, to achieve extensive large-scale applications, it is necessary to further explore environmentally friendly, low-cost, and controllable synthetic technologies to prepare high-performance Sb-based anode materials. This review provides specific perspectives for the construction and optimization of Sb-based anode materials and suggests scope for future work on Sb-based anode materials, thereby promoting the rapid development and practical application of SIBs.      

Revealing the Reaction and Fading Mechanism of FeSe2 Cathodes for Rechargeable Magnesium Batteries

Rechargeable Mg batteries (RMBs) are advantageous large-scale energy-storage devices because of the high abundance and high safety, but exploring high-performance cathodes remains the largest difficulty for their development. Compared with oxides and sulfides, selenides show better Mg-storage performance because the weaker interaction with the Mg²⁺ cation favors fast kinetics. Herein, nanorod-like FeSe₂ was synthesized and investigated as a cathode for RMBs. Compared with microspheres and microparticles, nanorods exhibit higher capacity and better rate capability with a smaller particle size. The FeSe₂ nanorods show a high capacity of 191 mAh g⁻¹ at 50 mA g⁻¹ and a good rate performance of 39 mAh g⁻¹ at 1000 mA g⁻¹. Ex situ characterizations demonstrate the Mg²⁺ intercalation mechanism for FeSe₂, and a slight conversion reaction occurs on the surface of the particles. The capacity fading is mainly because of the dissolution of Fe²⁺, which is caused by the reaction between Fe²⁺ and Cl⁻ of the electrolyte during the charge process on the surface of the particles. The surface of FeSe₂ is mainly selenium after long cycling, which may also dissolve in the electrolyte during cycling. The present work develops a new type of Mg²⁺ intercalation cathode for RMBs. More importantly, the fading mechanism revealed herein has considered the specificity of Mg battery electrolyte and would assist a better understanding of selenide cathodes for RMBs.     

固态锂电池界面优化策略的研究进展

固态锂电池具有安全性好、能量密度高等优点,在新能源汽车和智能电子等领域具有广泛的应用前景。然而,由化学/电化学和物理因素引起的界面副反应与高界面阻抗问题制约了其进一步发展。先前的综述已对解决化学/电化学界面问题的方法有了相对全面的阐述,但并未细致讨论不同结构固态电池中物理界面的影响及应对策略。本文将简要介绍化学/电化学界面问题及其解决方案;重点按结构特点将固态锂电池分为三明治结构、粉末复合结构和3D一体化结构,细致地分析不同电池结构的物理界面特点与优化策略,并对各种策略的优缺点进行比较分析;最后,对固态锂电池电极/电解质界面的未来研究方向进行展望。     

高比能锂离子电池层状富锂正极材料改性策略研究进展

层状富锂材料具有超过250 mAh∙g⁻¹的高可逆比容量,被认为是下一代高比能锂离子电池最具商业化前景的正极材料之一。然而,层状富锂材料在实际应用之前仍需解决诸多挑战,如高电压氧释放、层状到岩盐相的结构变化、过渡金属离子迁移等结构劣化,并由此带来了较低的初始库伦效率、电压/容量的衰减以及循环寿命的不足。针对以上问题,进行层状富锂材料改性无疑是一种行之有效的方法。本综述全面介绍了层状富锂材料的结构、组分以及电化学性能,在此基础上对材料改性策略进行了系统阐述,详细介绍了体相掺杂、表面包覆、缺陷设计、离子交换和微结构调控等一系列改性策略的现状以及发展趋势,最终提出了高容量和长循环层状富锂材料和高比能锂离子电池的设计思路。     

Syntheses, Crystal Structures and Characterization of Layered and Layer-pillared Zinc Arsonates

Two zinc arsonate coordination polymers, Zn(4-apa)·H2O (1, 4-apaH2 = 4-amino- phenylarsonatic acid) and Zn(4-apa) (2), have been hydrothermally synthesized and characterized by elemental analysis, IR and single-crystal and powder X-ray diffraction. Crystal data for 1: monoclinic, space group C2/c with a = 23.056(5), b = 5.4224(11), c = 15.027(3) , β = 121.22(3)°, V = 1606.6(6) ?3, Dc = 2.468 g·cm-3, F(000) = 1168, μ = 7.122 mm-1, Z = 8, the final R = 0.0309 and wR = 0.0752 for 1763 observed reflections with I > 2σ(I). For 2: monoclinic, space group P21/c with a = 8.7852(18), b = 9.2744(19), c = 9.752(2) , β = 103.45(3)°, V = 772.7(3)3, Dc = 2.410 g·cm-3, F(000) = 544, μ = 7.387 mm-1, Z = 4, the final R = 0.0321 and wR = 0.0741 for 1696 observed reflections with I > 2σ(I). The structure of 1 shows a two-dimensional (4,4)-network composed of an inorganic ladder chain bridged by the phenyl-linkers of 4-apa ligands. Compound 2 exhibits a 3D layer-pillared framework with crb net, in which inorganic (4-82)-networks are joined by the phenyl-linkers.     

邻苯二甲酸锌配合物的合成,红外光谱和晶体结构

邻苯二甲酸锌配合物的合成、红外光谱和晶体结构孙聚堂＊王东利张克立王春林（武汉大学化学系武汉４３００７２）（武汉大学测试中心武汉）关键词邻苯二甲酸，锌，晶体结构，红外光谱１９９６－１２－１６收稿，１９９７－０６－１６修回国家自然科学基金资助课题掺杂微量...