聚四氟乙烯在锌-空气电池中的应用

为了改进锌－空气电池空气电极的、配方及工艺,笔者选用憎水型聚合物聚四氟乙烯作为空气电极的制膜基材和粘结剂,对其在电极中的用量及工艺参数进行了优化研究,并利用扫描电镜对电极的表观形态进行了观察,从微观结构上对电极的结构与性能关系进行了探讨。研究结果表明,所制得的空气扩散电极的电化学性能良好,由其与锌电极组装成的电池样品放电容量高达３６００mAh以上。     

中性锌锰电池可充性的研究

介绍了在中性锌锰电池中加入醋酸钠，可使一次性锌锰电池具有一定的可充性，以及电解质溶液中醋酸钠的最佳含量。     

锌空气电池关键问题与发展趋势

电化学可充的锌-空气电池具有能量密度高、水系电解液安全和成本低等特点,是电能高效转换和储存的重要技术方向,无论作为动力电池用于纯电动汽车等移动交通工具,还是用于新能源发电过程储能,都具有广阔发展前景。但正极存在电极结构设计和催化剂开发问题,负极存在抑制枝晶、控制析氢和提高锌循环性能等挑战,严重阻碍了锌空气电池的商业化进程。本文详细分析了锌-空气电池的关键科学问题,尤其是关于空气电极的催化剂、电极结构、锌枝晶等问题,结合电池性能进行详尽讨论。归纳现有研究后认为:开发新型电催化剂和空气电极,发展循环寿命长、成本低的锌负极制造技术与工艺,是锌空气电池所面临的亟需解决问题和未来的发展趋势。     

水分交换对锌空气电池性能的影响

为了研究水分交换对锌空气电池性能的影响，本文分别测试了锌空气电池的吸水、失水性能及其恒流放电性能。结果表明，电池的吸水与环境湿度和电池内部的湿度差值直接相关，并且电池吸水对电池性能的影响大于电池失水对电池性能的影响，而锌空气电池吸水造成正极性能的衰减，是引起电池性能下降的主要原因。     

锌空气电池氧化还原催化剂的研究进展

结合近几年国内外锌空气电池阴极催化剂的研究成果,从碳材料催化剂、金属催化剂及金属化合物催化剂等方面综述了这几类催化剂研究现状,并对锌空气电池的发展进行了展望。     

水分交换对锌空气电池性能的影响

为了研究水分交换对锌空气电池性能的影响,本文分别测试了锌空气电池的吸水、失水性能及其恒流放电性能。结果表明,电池的吸水与环境湿度和电池内部的湿度差值直接相关,并且电池吸水对电池性能的影响大于电池失水对电池性能的影响,而锌空气电池吸水造成正极性能的衰减,是引起电池性能下降的主要原因。     

可充锌空气电池关键问题研究进展

可充锌空气电池具有能量密度高、资源丰富、价格低廉、反应活性物质绿色无污染等特点,被认为是一种有巨大市场前景的新一代电池,但可充锌空气电池存在的问题严重制约了其发展和商业化进程。因此,本文综述了可充锌空气电池锌阳极枝晶生长、形变、钝化、析氢腐蚀、电解质挥发和碳酸盐沉淀5个关键科学问题的研究进展,并展望了未来关于这些关键科学问题解决的切入点,对开发高效、耐久可充锌空气电池具有重要指导意义。     

锌—聚苯胺二次电池的性能研究

采用较简单的方法把化学法合成的聚苯胺粉末加工成电极,构成水溶液电解质的锌—聚苯胺二次电池,对电池在各种充放电条件下的性能进行了研究,发现电池具有较高的电容量、能量密度、库仑效率和较好的循环寿命,其适宜的工作条件是电解液的pH值应保持在4左右、充放电电压应限制在0.75～1.50V,充放电电流不得超过2.0mA/cm~2。     

中性锌锰电池中的无汞缓蚀剂

中性锌锰电池是用途最大的电池。一直以来，中性锌锰电池中都采用汞作为负极缓蚀剂。虽然汞具有很好的缓蚀性能，并能有效改善电池效果，但由于其会对环境造成很大的污染，中性锌锰电池无汞化具有特殊的意义。本文综述了国内外有关中性锌锰电池无汞缓蚀剂的研究现状，分析了各种无汞缓蚀剂在中性锌锰电池中的作用机理。     

碱性电解液中锌电极上钝化膜的测量

作者用“二级电势跳跃法”测量了锌电极上钝化膜的厚度。以锌圆盘电极为工作电极、汞-氟化汞电极为参比电极,氢氧化钾溶液为电解液。在不同的温度、碱度、钝化电势和圆盘转速下进行测量,钝化膜的厚度随操作条件改变而变化,但一般其数量级为500A,与以往用“椭圆偏振光法”所测得的结果相比,误差在10％以内。     

离子液体电解质在锂二次电池中的应用

锂二次电池作为动力电池,被寄予厚望。但锂二次电池面临的安全隐患也是不容忽视的,是当前亟需解决的问题,而这与电解质的性质有着紧密的联系。离子液体由于具有较宽电化学窗口、良好的导电性、高热稳定性、几乎无挥发及不燃烧等优良的特性,正在作为一种新型绿色替代溶剂被电化学领域所关注。离子液体的不燃烧特性,对于替代传统有机电解质具有十分重要的意义。本文阐述了新型溶剂“离子液体”作为电解质在锂二次电池中的应用,其中重点阐述了在碳、硅、钛酸锂(Li₄Ti₅O₁₂)、磷酸亚铁锂(LiFePO₄)、钴酸锂LiCoO₂、镍锰酸锂(LiNi_xMn_yO_z),镍钴锰锂(LiNi_xCo_yMn_zO_w)及在锂硫(Li-S)电池中的应用。     

有机电解液对锂离子电池合金型负极材料性能的影响

锂离子电池合金型负极材料的研究得到了广泛的关注,但是合金电极与电解液相互作用的研究非常少。本文采用电镀和热处理相结合的方法制备出Cu₆Sn₅合金薄膜电极,研究了各种电解液对电极性能的影响。研究结果表明,合金电极在LiN(CF₂SO₂)₂(LITFSI)为溶质的电解液中表现出比在常用的以LiPF₆作为溶质的电解液中更高的容量和更好的循环性能。合金薄膜电极在1mol·L^-1 LITFSI/EC∶DEC(1∶2)电解液中具有更小的反应电阻和更大的反应电流密度,锂离子在电极上插入和脱嵌的可逆性良好,反应电阻只有在1mol·L^-1 LiPF₆/PC电解液中的1/10。研究结果表明,乙烯碳酸酯(EC)由于在充放电过程中会形成固体电解质界面（SEI）膜,能大幅度提高材料的电化学性能,在锂离子电池中是不可或缺的。     

Supercritical carbon dioxide extraction of lithium-ion battery electrolytes

Two different separator materials (polyethylene fleece – Freudenberg 2190 and porous glass fiber – Whatman^® GF/D) and two different lithium-ion battery electrolytes have been investigated regarding their behavior in an autoclave extraction with supercritical helium head pressure carbon dioxide (sc HHPCO₂). Mixtures of dimethyl carbonate (DMC)/ethylene carbonate (EC) and ethylmethyl carbonate (EMC)/EC, each with 1 mol/L LiPF₆ were used.In addition to these proof of principle experiments, the developed extraction method was further applied to real battery samples. Commercial 18650 cells (after formation and aging) were opened and the jelly roll was extracted with sc HHPCO₂. Extracts were analyzed with gas and ion chromatography (GC, IC). Recovery rates and extract compositions strongly depend on the material of which the electrolyte is extracted. Further structure determination of electrolyte aging products was performed with different ionization modes in GC–mass spectrometry (GC–MS) experiments. Diethyl carbonate (DEC), dimethyl-2,5-dioxahexane dicarboxylate (DMDOHC), ethylmethyl-2,5-dioxahexane dicarboxylate (EMDOHC) and diethyl-2,5-dioxahexane dicarboxylate (DEDOHC) are aging products of electrolyte degradation which were successfully extracted and identified. Their concentrations correlate with solid electrolyte interphase (SEI) growth on the negative electrode which was investigated with scanning electron microscopy (SEM).     

Control of magnesium interfacial reactions in aqueous electrolytes towards a biocompatible battery

A stable magnesium battery has been developed based on a magnesium anode, a poly(dioxyethane thiophene) (PEDOT) cathode and a near-saturated aqueous solution of LiCl, MgCl₂, or mixture of these salts at pH of 11. This combination leads to a low water activity in the electrolyte, which thus suppresses the hydrogen evolution reaction on Mg, as well as producing a stable oxy-hydroxide film which protects the metal surface from freely corroding. The conducting polymer cathode is reduced somewhat during the discharge process, however, appears to be readily re-oxidised (as determined from the resistance) by the oxygen present in the cell. The cell is therefore primarily a Mg/O₂ battery, however, the PEDOT appears to enhance the performance, in particular the discharge voltage.     

Li-LiFePO4 rechargeable polymer battery using dual composite polymer electrolytes

A composite polymer electrolyte, formed by dispersing into a poly(ethylene oxide)-lithium salt matrix two additives, i.e. calyx(6)pyrrole, (CP) acting as an anion trapper and superacid zirconia, S-ZrO₂ acting as a conductivity promoter, has been tested as a separator in a new type of rechargeable lithium battery using lithium iron phosphate as the cathode. The choice of the electrolyte was motivated by its favourable transport properties both in terms of lithium ion transference number and of total ionic conductivity. The choice of the cathode was motivated by the value of its operating voltage which falls within the stability window of the electrolyte. The performance of the battery was determined by cycling tests carried out at various rates and at various temperatures. The results demonstrate the good rate capability of the battery which can operate at high charge-discharge efficiency even at 1 C rate and that it can be cycled at 90 °C with a satisfactory initial capacity of the order of 90 mAh g⁻¹. These values outline the practical relevance of the composite electrolyte membrane and of its use as separator in a lithium battery. H. H. Sumathipala—On leave from Department of Physics University of Kelaniya, Kelaniya, Sri Lanka.     

High‐energy density flow battery validation

A zinc‐alkaline flow cell was used to validate a new type of flow battery in which all reagents and products remain as solids on the electrodes. In every case, flow of electrolyte reduced overpotential losses when compared with operation without electrolyte flow. Large separation distances between the electrodes resulting from larger sections of separating tubing led to increased overpotential losses. A mass transfer mechanism is proposed that substantiates increasing overpotential with increasing electrode separation distances. Based on this mechanism, it was hypothesized that ion exchange packing would reduce the overpotential losses; this hypothesis was experimentally validated. © 2010 American Institute of Chemical Engineers AIChE J, 2011     

安全固态锂电池室温聚合物基电解质的研究进展

目前,大多数聚合物固态电解质在室温下离子电导率较低,约为10^–8 ~10^-6 S /cm,且对温度存在着较大的依赖性,仍无法满足高性能室温固态锂电池的实际应用需要。基于此,本文先介绍了室温聚合物电解质在锂离子电池中应用的主要研究进展及其优缺点。然后,从物理调控、化学调控等多角度重点阐述了室温聚合物电解质（包括全固态聚合物电解质、准固态聚合物电解质）的制备工艺、优化与改性方法、作用机理等在电池中应用的主要研究进展和现状。最后,对锂离子电池用室温聚合物电解质存在的挑战和未来可能发展趋势进行了展望。     

Effect of the addition of hydrophobic clay on the electrochemical property of polyacrylonitrile/LiClO4 polymer electrolytes for lithium battery

In this study, an organoclay, ALA-MMT, was prepared by the ionic exchange reaction of montmorillonite (MMT) with 12-aminododecanoic acid (ALA). ALA-MMT was then used as a filler to prepare a series of composite polymer electrolytes based on polyacrylonitrile (PAN) and LiClO₄. The effect of the addition of ALA-MMT on the properties of the composite polymer electrolytes (CPEs) was investigated by XRD, FT-IR, DSC, tensile strength, AC impedance, and cyclic voltammetry measurements. It was found that the ALA-MMT particles were well dispersed in the CPEs. Owing to the incorporation of ALA-MMT, a higher fraction of the free anions was obtained, indicating that the lithium salt dissolved in the PAN matrix more effectively for the CPE than in the PAN/LiClO₄ polymer electrolyte. Moreover, the glass-transition temperature was reduced, benefiting the ion transport. The best ionic conductivity at room temperature was obtained from the CPE with 7 wt% of the modified clay and 0.6 M LiClO₄ per PAN repeat unit (CPE-7) and was more than seven times higher than that from the corresponding PAN/LiClO₄ polymer electrolyte (CPE-0). The mechanical property and the cation transference number, t₊, of CPE-7 are largely increased compared to that of CPE-0. Besides, the CPEs were electrochemically stabilized up to 4.75 V and the corresponding cell exhibited excellent electrochemical stability and cyclability over the potential range between 0 V and 4.0 V vs. Li/Li⁺.     

Effect of additives in PEO/PAA/PMAA composite solid polymer electrolytes on the ionic conductivity and Li ion battery performance

Polyethylene oxide (PEO) based-solid polymer electrolytes were prepared with low weight polymers bearing carboxylic acid groups added onto the polymer backbone, and the variation of the conductivity and performance of the resulting Li ion battery system was examined. The composite solid polymer electrolytes (CSPEs) were composed of PEO, LiClO_4, PAA (polyacrylic acid), PMAA (polymethacrylic acid), and Al₂O₃. The addition of additives to the PEO matrix enhanced the ionic conductivities of the electrolyte. The composite electrolyte composed of PEO:LiClO₄:PAA/PMAA/Li_0.3 exhibited a low polarization resistance of 881.5 ohms in its impedance spectra, while the PEO:LiClO₄ film showed a high value of 4,592 ohms. The highest ionic conductivity of 9.87 × 10⁻⁴ S cm⁻¹ was attained for the electrolyte composed of PEO:LiClO₄:PAA/PMAA/Li_0.3 at 20 °C. The cyclic voltammogram of Li⁺ recorded for the cell consisting of the PEO:LiClO₄:PAA/PMAA/Li_0.3:Al₂O₃ composite electrolyte exhibited the same diffusion process as that obtained with an ultra-microelectrode. Based on this electrolyte, the applicability of the solid polymer electrolytes to lithium batteries was examined for an Li/SPE/LiNi_0.5Co_0.5O₂ cell.     

全固态锂离子电池技术进展及现状

锂离子电池电解质多为有机液体,易燃易爆、安全性差。用固态电解质制备的全固态锂离子电池,具有电化学窗口宽、能量密度大和安全性高等优点,是电动汽车和规模化储能应用的理想化学电源。本工作主要介绍了全固态电解质的电解质材料及电极/电解质界面调控与机理问题,为改善固/固界面相容性及降低界面阻抗方面提供解决方案。阐述了目前主流的正负极材料、全固态锂离子电池的设计及目前的专利申请状况,简要讨论了全固态锂离子电池面临的主要问题,并从产业应用角度展望了其应用现状和未来发展趋势,为从业者全面了解全固态电池的发展提供有利依据。