高容量锂离子电池正极复合材料pillar[5]quinone/CMK-3的制备

以有机醌类化合物柱[5]醌(pillar[5]quinone,P5Q)作为锂离子电池的正极材料,探索了其储锂性能。实验结果表明,P5Q首圈放电容量达到了431 mAh·g^-1,显示出100%的活性位点利用率。然而,P5Q在电解液中的溶解会导致循环过程中容量的衰减。采用超声法将P5Q填入有序介孔碳CMK-3的孔道,制备了P5Q/CMK-3复合材料,以此减少P5Q与电解液的接触,从而减缓了P5Q的溶解速率,提高了电池的循环稳定性。P5Q/CMK-3复合材料100次充放电循环后容量为300 mAh·g^-1,保持率高达71%,说明了该优化方法效果显著,提高了P5Q在锂离子电池中的实际应用价值。     

LiFePO4在饱和LiNO3溶液中的锂化行为

锂离子电池是目前应用最广泛的二次电池,均利用有机电解液。然而,有机体系锂离子电池存在易燃、易爆的安全隐患,限制了其使用范围。水溶液锂离子电池作为一类新型的二次电池[1￣10],使用水溶液电解液代替有机电解液,消除了因有机电解液与电极材料反应形成枝晶可能造成的燃烧、爆炸等安全隐患,使其在低电压电池如铅酸电池、碱锰电池等领域的应用有很大的竞争潜力[10]。目前,大量研究集中在选择合适的电极材料来组装水溶液锂离子电池,文献报道的水溶液锂离子电池正极材料主要有LiMnO4[1￣9]、LiNi1-xCoO2[10],但是LiMnO4在循环约20次后容…     

高容量有机正极材料杯[4]醌在离子液体中的储锂性能

选用理论容量高达446 mAh·g~(-1)的杯[4]醌(calix[4]quinone,C4Q)作为正极材料,研究其储锂性能。由于C4Q在常规有机电解液中的溶解问题会在一定的程度上限制其性能最大化,我们选用Li[TFSI]/[PY13][TFSI]([PY13][TFSI]:1-丙基-1-甲基吡咯烷鎓双三氟甲基磺酰亚胺)离子液体电解液与C4Q进行匹配组装锂离子电池,较大程度地提升了其循环稳定性和倍率性能。在0.1C的电流密度下,循环100圈后的放电比容量为280 mAh·g~(-1),1 000圈后的容量保持率高达72%。当电流密度增加至1C时,放电容量仍有154 mAh·g~(-1)。     

Mg、F共掺杂锂锰尖晶石的合成与性能研究

锂锰尖晶石LiMn2O4被认为是当前最有前途的锂离子电池的正极材料之一[1];特别在用于动力锂离子电池方面.但是LiMn2O4在充-放电循环过程中会发生严重的容量衰减;而产生容量衰减的主要原因是其结构的不稳定性[2-3]、锰的溶解[4]和John-Teller效应[5].     

球磨微波法制备Li3V2（PO4）3/C及其电化学性能表征

本文采用球磨微波法合成锂离子电池正极材料Li3V2(PO4)3/C,并研究了微波辐射时间对样品电化学性能的影响.结果表明,640 W微波辐射18 min合成的材料,结晶度高,粒径小而均匀.该电极5C倍率下首次放电比容量达101.3 mAh·g-1,300周期循环,其放电比容量仍保持100.8 mAh·g-1,展示出良好的应用前景.     

金属有机框架(MOFs)材料在锂离子电池及锂金属电池电解液中的应用

总结了金属有机框架(MOFs)材料在锂离子电池电解液中的研究进展. 通过归纳锂离子电池长期存在的一些缺陷, 随后将MOFs材料作为离子筛、人造负极保护层、准固态电解质以及用来调节电解液构型, 使得锂离子电池的性能得到显著提升. 最后, 基于MOFs材料本身的特性, 还对MOFs材料在电化学储能领域中的后续应用进行了合理地前瞻性展望.     

Al掺杂尖晶石LiMn2O4正极材料的性能

尖晶石LiMn2O4作为锂离子电池正极可大电流放电,且成本低、环境友好.采用溶胶-凝胶法制备尖晶石LiMn2O4及Al掺杂材料.使用X-射线衍射(XRD)和扫描电子显微镜(SEM)观察材料结构与形貌.结果表明,复合材料颗粒尺寸300-500 nm,呈类球形.电化学恒流充放电测试表明,Al掺杂尖晶石LiMn2O4电极的循环性明显提高,Al掺杂5%LiMn2O4(by mass,下同)正极在1C倍率充放电100周期循环后的容量保持率为98.2%,1C倍率充电、5C倍率放电下,100周期循环后其容量保持率为99.0%,表现出较优的电化学循环性能.     

有机电极材料在非水系金属镁二次电池中的研究进展

由于镁资源储量丰富、成本低廉, 且金属镁具有理论体积比容量高(3833 mAh/cm³), 沉积/溶解过程中不易形成枝晶等优点, 金属镁二次电池受到了研究者的广泛关注. 然而, Mg²⁺较大的极性导致其在多数锂离子电池正极材料中无法实现可逆脱嵌. 主流无机电极材料普遍存在只能在较小电流密度下循环、动力学缓慢、制备工艺复杂等问题. 相较而言, 有机电极材料具有理论比容量高、结构多样易调控、资源丰富、环境友好、受离子半径和电荷影响小等优点, 被认为是一种有潜力的电极材料. 综述了近年来用于非水系镁二次电池有机正极材料的研究进展, 讨论了不同类型有机正极材料的电荷存储机制及电化学性能, 并总结了其面临的挑战、解决策略以及未来的发展方向.     

锂离子电池正极材料Li_3V_2(PO_4)_3/C的制备及电化学性能

以球磨结合焙烧的方法制备锂离子电池正极材料Li3V2(PO4)3/C.XRD、EIS表征及以该材料作正极的恒电流循环测试表明,所得产物为晶体结构发育良好的单斜晶系Li3V2(PO4)3.在0.1C、0.25C和0.5C倍率下,首次放电比容量分别为150.6、134.1和107.1mAh·g-1.0.25C循环130周后容量保持率为87.3%,而0.5C循环105周后容量保持率仍达到87.2%.锂离子在材料中的嵌入、脱出伴随明显的两相转变过程.电荷传递阻抗和SEI膜阻抗是影响材料倍率性能的主要因素.     

锂离子电池有机硫化物电极材料*

有机硫化物电极材料是一类新型高比容量的储能材料,通过S-S键的可逆断裂与键合进行释能与储能,主要应用于锂离子电池的正极。该材料包括有机二硫化物、有机多硫化物和硫化聚合物等。本文综述了有机硫化物电极材料的研究现状,分析了各种材料的优势与不足,并展望了其发展趋势。如何提高现有材料的比容量并改善其循环性能是目前的研究重点。     

有机盐PTO(KPD)2作为高性能锂离子电池正极材料的研究

采用溶剂热反应合成了一种新型的有机盐材料芘四酮-二均苯四甲酸二酰亚胺二钾盐PTO(KPD)₂. 该材料作为锂离子电池正极时, 表现出优异的循环和倍率性能. 研究结果表明, 在50 mA/g电流密度下, PTO(KPD)₂的实际放电比容量达到255.8 mA·h/g; 在500 mA/g电流密度下循环800次后, 容量保持率为81.1%. PTO(KPD)₂盐结构的形成提高了分子极性, 大大降低了其在电解液中的溶解度, 使得材料表现出优异的电化学性能.     

Superior performance for lithium-ion battery with organic cathode and ionic liquid electrolyte

Organic small structure quinones go with ionic liquids electrolytes would exhibit ultrastable electrochemical properties.In this study,calix[6]quinone(C6Q) cathode was matched with ionic liquid electrolyte Li[TFSI]/[PY13][TFSI](bis(trifluoromethane)sulfonimide lithium salt/N-methyl-N-pro pylpyrrolidinium bis(trifluoromethanesulfonyl)amide) to assemble lithium-ion batteries(LIBs).The electrochemical performance of LIBs was systematically studied.The capacity retention rates of C6Q through 1000 cycles at current densities of 0.2 C and 0.5 C were 70% and 72%,respectively.At 5 C, the capacity was maintained at 190 mAh g^-1 after 1000 cycles,and 155 mAh g^-1 even after 10,000 cycles,comparable to inorganic materials.This work would give a big push to the practical process of organic electrode materials in energy storage.     

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 redox-active conjugated microporous polymer cathode for highperformance lithium/potassium-organic batteries

Organic redox-active materials have emerged as a class of electrode materials for rechargeable batteries due to their high redox activity,low cost,structure diversity and flexibility.However,the high solubility of organic small molecules in organic electrolytes commonly leads to the fast capacity decay with cycling.Herein,we report a redox-active conjugated microporous polymer of poly(pyrene-co-anthraquinone)(Py Aq)cathode material consisting of pyrene and anthraquinone units.Benefiting from the highly cross-linked polymer structure with insoluble nature in organic electrolytes,the high surface area and the plentiful redox-active carbonyl groups,the Py Aq cathode demonstrates outstanding electrochemical performances for both lithium-ion batteries(LIBs)and potassium-ion batteries(KIBs).Specifically,the Py Aq cathode for LIBs delivers a high reversible capacity of 169 m Ah g^-1 at the current density of 20 m A g^-1,a high rate capability(142 m Ah g^-1 at 1000 m A g^-1)and an excellent cycling stability for 4000 cycles.Additionally,the Py Aq cathode for KIBs also exhibits a high reversible capacity of143 m Ah g^-1 with a long cycling life over 800 cycles.The excellent electrochemical performance demonstrates that the newly developed Py Aq could be an attractive cathode material for the advanced energy storage technologies.     

锂离子电池正极材料LiCoO2的制备新方法

利用电解金属钴制得Co(OH)_2-2xR_x(其中R为有机酸和无机酸根离子)中间产物,然后根据钴含量与LiOH·H₂O)固相反应制得了LiCoO₂.通过X光衍射,扫描电镜以及激光粒度测试表明,所得的锂离子正极材料LiCoO₂结构纯正,粒度分布集中,比表面积较大:对其进行充放电实验表明,放电容量比较高,首次放电容量达到146mAh/g,循环10次后容量仍保持在142mAh/g.该法可大大降低制备LiCoO₂的生产成本,具有十分广阔的应用前景.     

Ion exchange membranes as electrolyte to improve high temperature capacity retention of LiMn(2)O(4) cathode lithium-ion batteries

A LiMn(2)O(4) cathode lithium-ion battery using lithiated ion exchange membranes swollen with organic non-aqueous solvent as the electrolyte to overcome capacity fading at high temperature is first demonstrated, and shows very good capacity retention compared with conventional lithium-ion batteries using liquid electrolyte.     

PEO基聚合物电解质及其锂硫电池性能研究

锂硫电池由于具有高的理论比能量引起了广泛关注,然而传统液态锂硫电池由于多硫化物的“穿梭效应”以及安全问题而限制了其应用,全固态锂硫电池可显著提高电池安全性能并有望解决多硫化物的穿梭问题. 本文采用传统的溶液浇铸法制备了具有不同的[EO]/[Li⁺]的PEO-LiTFSI聚合物电解质,并将其应用于锂硫电池. 研究发现,虽然[EO]/[Li⁺] = 8的聚合物电解质具有更高的离子电导率,但是[EO]/[Li⁺] = 20的电解质与金属锂负极间的界面阻抗更低,界面稳定性更好. Li|PEO-LiTFSI([EO]/[Li⁺]=20)|Li对称电池在60 °C,电流密度为0.1 mA·cm^-2时可稳定循环超过300 h,而Li|PEO-LiTFSI ([EO]/[Li⁺]=8)|Li对称电池循环75 h就出现了短路现象. 基于PEO-LiTFSI([EO]/[Li⁺]=20)电解质的锂硫电池首圈放电比容量为934 mAh·g^-1,循环16圈后放电比容量为917 mAh·g^-1以上. 而基于PEO-LiTFSI ([EO]/[Li⁺]=8)电解质的锂硫电池,由于与锂负极较低的界面稳定性不能够正常循环,首圈就出现了严重过充现象.     

Improving the stability of LiNi_(0.80)Co_(0.15)Al_(0.05)O_2 by AlPO_4 nanocoating for lithium-ion batteries

Nickel-rich layered materials,such as LiNi_(0.8)0Co_(0.15)Al_(0.05)O_2(NCA),have been considered as one alternative cathode materials for lithium-ion batteries(LIBs) due to their high capacity and low cost.However,their poor cycle life and low thermal stability,caused by the electrode/electrolyte side reaction,prohibit their prosperity in practical application.Herein,AlPO4 has been homogeneously coated on the surface of NCA via wet chemical method towards the target of protecting NCA from the attack of electrolyte.Compared with the bare NCA,NCA@AlPO_4 electrode delivers high capacity without sacrificing the discharge capacity and excellent cycling stability.After 150 cycles at 0.5 C between 3.0-4.3 V,the capacity retention of the coated material is 86.9%,much higher than that of bare NCA(66.8%).Furthermore,the thermal stability of cathode is much improved due to the protection of the uniform coating layer on the surface of NCA.These results suggest that AlPO4 coated NCA materials could act as one promising candidate for next-generation LIBs with high energy density in the near future.     

Anion-Dependent Redox Chemistry of p-Type Poly(vinyldimethylphenazine) Cathode Materials

Metal-free organic electrode materials have attracted vast research attention owing to their designable structures and tunable electrochemical properties. Although n-type cathode materials could be used in various metal-ion batteries, p-type ones with high potential can deliver high energy density. Herein, we report a new p-type polymeric cathode material, poly(2-vinyl-5,10-dimethyl-dihydrophenazine) (PVDMP), with a theoretical capacity of 227 mAh g⁻¹. PVDMP featuring two-step redox reaction will be doped by two anions to maintain electroneutrality during oxidation, which resulted in an anion-dependent electrochemical behavior of PVDMP-based cathode. The suitable dopant anion for PVDMP was selected and the doping mechanism was confirmed. Under the optimized condition, PVDMP cathode can deliver a high initial capacity of 220 mAh g⁻¹ at 5 C and even remains 150 mAh g⁻¹ after 3900 cycles. This work not only provides a new kind of p-type organic cathode materials but also deepens the understanding of its anion-dependent redox chemistry.