A delicately designed functional binder enabling in situ construction of 3D cross-linking robust network for high-performance Si/graphite composite anode

The silicon (Si)-based anodes suffer from large volume expansion in the lithiation process. Aiming at improving the cycling stability of a Si/graphite composite anode processed by chemical vapor deposition (CVD) method, a functional aqueous binder was delicately designed and synthesized via an aqueous copolymerization of lithium acrylate and vinyl triethoxy silane (VTEO). The PAA-VTEO binder can in situ react with the silanol groups on the surface of Si nanoparticles to form a robust 3D cross-linked network. The resulting extremely high modulus and hardness of this integrated 3D network structure effectively restrained the volume expansion effect and significantly enhanced the electrochemical cycling stability of the CVD-Si@graphite composite anode. This work will provide new perspectives in designing functional binder for Si-based anodes.     

Influence of Calcination on the Properties of Nickel Oxide-Samarium Doped Ceria Carbonate (NiO-SDCC) Composite Anodes

Apart from its composition, the starting powder properties such as particle size potentially affect the triple phase boundary and the electrochemical performance. Calcination process has been identified as one of the factors that influence the particle size of the composite anode powders. This study investigates the correlation between calcination temperature and properties (i.e., chemical, physical, and thermal) of NiO–samarium-doped ceria carbonate (SDCC) composite anodes. NiO–SDCC composite anode powder was prepared with NiO and SDCC through high-energy ball milling. The resultant composite powder was subjected to calcination at various temperatures ranging from 600 °C to 800 °C. Characterizations of the composite anode were performed through X-ray diffraction (XRD), Fourier transform infrared spectroscopy, energy dispersive spectroscopy, field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), dilatometry, and porosity measurements. The composite anodes exhibited good chemical compatibility during XRD after calcination and sintering. The FTIR result verified the existence of carbonates in all the composite anodes. The increment in calcination temperature from 600 °C to 800 °C resulted in the growth of nanoscale particles, as evidenced by the FESEM micrographs and crystallite size. Nonetheless, the porosity obtained remained within the acceptable range for a good anodic reaction (20% to 40%). The TGA results showed gradual mass loss in the range of 400 °C to 600 °C (within the low-temperature solid oxide fuel cell region). The composite anodes calcined at 600 °C and 700 °C revealed a good thermal expansion coefficient that matches that of the SDCC electrolyte.     

LSGMC5含量对于二甲醚燃料电池复合Ni-Fe阳极性能的影响

用浸渍法制备了掺杂不同质量分数的La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ (LSGMC5)粉末的Ni8-Fe2-LSGMC5复合阳极, 并采用交流阻抗和直流极化技术考察了以氢气和二甲醚为燃气时该复合阳极的电化学性能及相应电池的功率输出特性. 结果表明, 在电极中掺入LSGMC5 粉末, 能显著地改善电极的形貌和电极/电解质界面结构, 减小欧姆电阻和极化电阻. 电极中LSGMC5 粉末含量对于氢气及二甲醚电化学氧化性能的影响显著不同. 以二甲醚为燃气时, 电极极化电阻随LSGMC5 粉末含量的增加而减小, 其中LSGMC5 掺杂量为30%的复合阳极具有最高的电化学性能, 相应电池在1073、1023、973 K 时的输出功率分别为1.00、0.61、0.40 W·cm-2; 以氢气为燃气时, LSGMC5 掺杂量为20%的复合阳极具有最好的电化学性能, 随着LSGMC5 掺杂量的进一步增加, 电极极化电阻显著增大.     

A novel method to fabricate lithium-ion polymer batteries based on LiMn<Subscript>2</Subscript>O<Subscript>4</Subscript>/NG electrodes

A novel method to fabricate lithium-ion polymer batteries (LiPBs) has been developed. The LiPBs was fabricated without microporous polyolefin separators, taking spinel lithium manganese oxide (LiMn₂O₄) and natural graphite (NG) as the electrodes. The thicknesses of the cathodes and the anodes are 190 and 110 μm, respectively. The NG anode was coated with a microporous composite polymer film (20 μm thick) which composed of polymer and ultrafine particles. The coating process was effective and simple to be used in practical application, and ensured the composite polymer film to act as a good separator in the LiPB. The LiPBs assembled with the coated NG anodes and pristine LiMn₂O₄ cathodes presented better electrochemical performances than liquid lithium-ion battery counterparts, proving that the microporous composite polymer film can improve the performance of the coated NG anode. In this paper, the spinel LiMn₂O₄/(coated)NG-based LiPBs exhibited high rate capability, compliant temperature reliability, and significantly, excellent cycling performance under the elevated temperature (55°C).     

轻质三维多孔泡沫铝用作高性能锂金属负极骨架

将轻质、三维多孔且亲锂的泡沫铝用作锂(Li)金属负极骨架,通过简单的机械挤压方法,将泡沫铝与金属Li复合,制得Al@Li复合负极。泡沫铝自身的高亲锂性,能够为Li金属成核提供丰富且均匀的活性位点,诱导Li在泡沫铝内部的快速成核和均匀电沉积。同时,泡沫铝的三维多孔结构,可以容纳Li金属负极在充放电过程中的巨大体积应变,降低局部电流密度,从而有效抑制Li枝晶的生长。因此,与纯Li金属负极相比,所获得的Al@Li复合负极在对称电池和LiFePO₄||Al@Li半电池中,均表现出了更加优异的循环稳定性。     

轻质三维多孔泡沫铝用作高性能锂金属负极骨架

将轻质、三维多孔且亲锂的泡沫铝用作锂(Li)金属负极骨架,通过简单的机械挤压方法,将泡沫铝与金属 Li复合,制得Al@Li复合负极。泡沫铝自身的高亲锂性,能够为Li金属成核提供丰富且均匀的活性位点,诱导Li在泡沫铝内部的快速成核和均匀电沉积。同时,泡沫铝的三维多孔结构,可以容纳Li金属负极在充放电过程中的巨大体积应变,降低局部电流密度,从而有效抑制Li枝晶的生长。因此,与纯Li金属负极相比,所获得的Al@Li复合负极在对称电池和LiFePO₄||Al@Li半电池中,均表现出了更加优异的循环稳定性。     

Electrochemical Behavior of (Fe,Ni)Ox-Based Anodes for Solid-Oxide Fuel Cells in Methane-Containing Atmospheres

Russian Journal of Electrochemistry - The work is devoted to investigation of the electrochemical behavior of (Fe,Ni)Ox-based composite anodes in the hydrogen- and methane-containing fuel. Among...     

Study of tin dioxide–sodium stannate composite obtained by decomposition of peroxostannate as a potential anode material for lithium-ion batteries

A tin dioxide–sodium stannate composite has been obtained by the thermal treatment of sodium peroxostannate nanoparticles at 500°C in air. X-ray powder diffraction study has revealed that the composite includes crystalline phases of cassiterite SnO₂, sodium stannate Na₂Sn₂O₅, and sodium hexahydroxostannate Na₂Sn(OH)₆. Scanning electron microscopy has shown that material morphology does not change considerably as compared with the initial tin peroxo compound. Electrochemical characteristics have been compared for the anodes of lithium-ion batteries based on tin dioxide–sodium stannate composite and anodes based on a material manufactured by the thermal treatment of graphene oxide–tin dioxide–sodium stannate composite at 500°C in air.     

锂金属电池中的复合负极

锂金属具有理论比容量高、电位低等优点,被认为是电极中的“圣杯”。然而,锂金属负极在循环过程当中存在着不可控的枝晶生长、体积膨胀等问题,严重地阻碍了锂金属电池的商业化进程。本综述首先概述了锂枝晶的形成机理,然后对由小及大,自内而外,总结了近年来三种不同层次的锂金属电池复合负极:锂金属负极内部结构的复合、锂金属电池内部结构的复合以及锂金属电池内部环境与外界操作条件的复合。最后,本综述对未来多层次锂金属电池复合负极的前景做出了展望。     

PPy‐encapsulated SnS2 Nanosheets Stabilized by Defects on a TiO2 Support as a Durable Anode Material for Lithium‐Ion Batteries

Nanostructured‐alloy‐type anodes have received great interest for high‐performance lithium‐ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy‐type anodes by creating defects on the surface of the metal oxide support is proposed. As a demonstration, PPy‐encapsulated SnS₂ nanosheets supported on defect‐rich TiO₂ nanotubes were produced and investigated as an anode material for LIBs. Both experimental results and theoretical calculations demonstrate that defect‐rich TiO₂ provides more chemical adhesions to SnS₂ and discharge products, compared to defect‐poor TiO₂, and then effectively stabilizes the electrode structure. As a result, the composite exhibits an unprecedented cycle stability. This work paves the way to designing durable and active nanostructured‐alloy‐type anodes on oxide supports.     

担载纳米硅的锂-碳复合微球作为锂二次电池负极

金属锂由于其极高的理论比容量(3860mAh·g~(-1),2061mAh·cm~(-3))和低的还原电势(相对于标准氢电极(SHE)为-3.04 V)等特点,成为了高能量密度锂电池负极材料的极佳选择之一。从上个世纪七十年代开始,科研工作者便开始了金属锂负极的研究,然而,由于金属锂与电解液反应严重,镀锂过程体积膨胀大,且在循环中易生成枝晶,以金属锂为负极的电池循环稳定性差,而且容易短路从而带来安全隐患。因此金属锂做为锂电池负极的商业化推广最终没有成功。在本工作中,我们在前期设计的锂-碳纳米管复合微球(Li-CNT)中引入了纳米硅颗粒制备了硅颗粒担载的锂-碳复合球(LiCNT-Si)。实验发现,纳米硅颗粒的加入不仅提高了锂-碳复合微球的载锂量(10%(质量百分含量)的硅添加量使得比容量从2000 mAh·g~(-1)提高到2600 mAh·g~(-1)),降低了锂的沉积/溶解过电势,有利于引导锂离子回到复合微球内部沉积,大大提高了材料的循环稳定性。同时,担载了纳米硅颗粒的锂-碳复合球也继承了锂-碳复合微球循环过程中体积膨胀小,不长枝晶的优点。而且添加的纳米硅颗粒还填充了Li-CNT微球中的孔隙,减少了电解液渗入复合微球内部腐蚀里面的金属锂,进一步提高了材料的库仑效率。以添加10%硅的锂碳复合材料作为负极,与商用磷酸铁锂正极组成全电池,在常规酯类电解液中1C (0.7 mA·cm~(-2))条件下能稳定循环900圈以上,库仑效率为96.7%,大大高于同样条件下测得的Li-CNT复合材料(90.1%)和金属锂片(79.3%)的库仑效率。因此,这种通过简单的熔融浸渍法即可制备的,具有高的比容量和长的循环稳定性的锂硅-碳复合材料具有较大的潜能成为高能量密度电池的负极材料,尤其适用于锂硫、锂氧这种正极不含锂源的电池体系。     

Effect of MWCNT on the performances of the rounded shape natural graphite as anode material for lithium-ion batteries

Multi-walled carbon nanotube (MWCNT) with bundle-type morphology was introduced as a new functional additive working as a particle connector or an expansion absorber in the anodes of lithium-ion batteries. By controlling the dispersion process, the MWCNT bundles were successfully divided and dispersed between the host particles. The composite anode consisting of rounded shape natural graphite and 2 wt.% of MWCNT exhibited the capacity of 300 mAh g⁻¹ at 3 C rate and excellent cyclability. The well-dispersed MWCNT bundles made it possible to relieve the large strains developed at high discharge C rates and to keep the electrical contact between the host particles during repeated intercalation/deintercalation. This study has also emphasized that when high C-rate applications of lithium-ion batteries are targeted, it is important to get optimum content of MWCNT as well as uniform dispersion of their bundles in the composite anodes.     

掺杂F-对PbO2阳极性能和电催化活性的影响

采用热分解-电镀法制备了Ti基PbO₂阳极(PbO₂阳极)和F^-掺杂PbO₂阳极(F-PbO₂阳极)。应用XRD和SEM技术对这两种电极进行了表征，采用加速电解寿命测试研究了其在硫酸溶液中的电解稳定性。结果表明，F-PbO₂阳极的寿命远大于PbO₂阳极的寿命，在4-氯苯酚(4-CP)的电催化降解过程中，F-PbO₂阳极表现出比PbO₂阳极较强的催化活性。本文对F^-掺杂提高PbO₂阳极性能和电催化活性的机理进行了探讨。并应用高效液相色谱确定了4-CP在F-PbO₂阳极上的降解历程。     

Si/Ti_xSi_y复合物的合成及其锂离子电池负极性能研究

通过机械球磨和高温热处理合成得到Si和Ti_xSi_y纳米颗粒复合物Si/Ti_xSi_y,并对该化合物进行X射线能谱(EDX)、X射线衍射(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)表征.合成的Si/Ti_xSi_y和机械球磨的Si/TiO_2都被用于锂离子电池的负极材料,Si/Ti_xSi_y表现出优越的充放电性能、较好的循环稳定性和倍率性能.     

P(VDF-HFP)-PMMA/CaCO3(SiO2)复合聚合物电解质的电化学性质

采用激光扫描共焦显微镜、X射线衍射、循环伏安和交流阻抗等方法对由聚(偏二氟乙烯-六氟丙烯)(P(VDF-HFP))、聚甲基丙烯酸甲酯(PMMA)以及纳米碳酸钙(二氧化硅)制备的几种复合聚合物电解质(CPE)膜P(VDF-HFP)-PMMA/CaCO3(SiO2)的性能进行了研究. 结果表明, PMMA的加入能提高CPE的吸液率, 从而增大其离子导电率. 在P(VDF-HFP)与PMMA质量比为1:1条件下制得的CPE性能最佳. 用P(VDF-HFP)-PMMA为聚合物基体与纳米级SiO2、CaCO3进行复合制成的聚合物膜, 无机粒子的加入没有破坏原来聚合物非晶结构; 室温下CPE的电导率达到3.42 mS·cm-1; 电化学稳定窗口为4.8 V. 电池Li/CPE/GMS(石墨基材料)的测试证明, CPE与石墨负极有很好的相容性. 聚合物电池Li/CPE(CaCO3)/LiCoO2比Li/CPE)(SiO2)/LiCoO2具有更优越的倍率放电性能.     

稳定锂电化学沉积和溶解行为的LiC6异质微结构界面层

本文采用机械辊压方法在金属锂表面通过原位固相反应生成LiC₆异质微结构界面层,并研究了在碳酸酯有机电解液体系下该异质层对锂电化学沉积和溶解行为的影响。通过形貌表征与电化学测试发现,LiC₆异质层能够有效提升锂电化学沉积的可逆性与均匀性,从而抑制枝晶生长及维持沉积/溶解界面的稳定。使用异质层改性金属锂负极的扣式全电池也较纯金属锂负极体系表现出更为优异的循环稳定性。     

Amorphous hollow carbon film as a flexible host for liquid Na-K alloy anode

Compared with solid alkali metal anodes (Li, Na, K), liquid metal anodes (LMAs) could enable high-energy batteries due to their unique advantages, such as self-healing property and no dendrites. Among LMAs, liquid Na-K alloy anode has become a hotspot due to its high theoretical capacity, low redox potential and formation at room temperature (RT). However, it is challenging to utilize liquid Na-K alloy directly and independently as an electrode; and the high surface tension makes it more difficult to immerse into porous current collectors at RT. Herein, an amorphous hollow carbon film (AHCF) consisting of hollow spheres with significant surface defects has been designed to quickly infiltrate Na-K liquid alloy into the hollow carbon film at RT, forming a composite electrode (Na-K@AHCF). The symmetric cell with Na-K@AHCF could exhibit a cycle lifespan up to 400 h at 0.1 mA/cm² and achieve stable stripping/deposition even at 5 mA/cm². When matching with cathode material of sulfurized polyacrylonitrile (SPAN), the obtained K-S full cell exhibits good cycle stability and rate performance.     

Improvement of cyclability of silicon-containing carbon nanofiber anodes for lithium-ion batteries by employing succinic anhydride as an electrolyte additive

Si/C composite nanofibers were prepared by electrospinning and carbonization using polyacrylonitrile as the spinning medium and carbon precursor. The effect of electrolyte additive succinic anhydride (SA) on the electrochemical performance of Si/C composite nanofiber anodes was investigated. Results show that after 50 cycles, the discharge capacity of Si/C composite nanofiber anode with the SA-added electrolyte is 34 % higher than that with additive-free electrolyte. At 150th cycle, the capacity retention of Si/C composite nanofiber anode with SA-added electrolyte is 82 % under 70 % state-of-charge. It is demonstrated that adding additive SA in the electrolyte is an effective and economic way to improve the cyclability of high-capacity Si/C composite nanofibers for next-generation high-energy lithium-ion batteries.     

Doped CeO2-LaFeO3 composite oxide as an active anode for direct hydrocarbon-type solid oxide fuel cells

Direct utilization of hydrocarbon and other renewable fuels is one of the most important issues concerning solid oxide fuel cells (SOFCs). Mixed ionic and electronic conductors (MIECs) have been explored as anode materials for direct hydrocarbon-type SOFCs. However, electrical conductivity of the most often reported MIEC oxide electrodes is still not satisfactory. As a result, mixed-conducting oxides with high electrical conductivity and catalytic activity are attracting considerable interest as an alternative anode material for noncoke depositing anodes. In this study, we examine the oxide composite Ce(Mn,Fe)O(2)-La(Sr)Fe(Mn)O(3) for use as an oxide anode in direct hydrocarbon-type SOFCs. High performance was demonstrated for this composite oxide anode in direct hydrocarbon-type SOFCs, showing high maximum power density of approximately 1 W cm(-2) at 1073 K when propane and butane were used as fuel. The high power density of the cell results from the high electrical conductivity of the composite oxide in hydrocarbon and the high surface activity in relation to direct hydrocarbon oxidation.     

A glucose/hydrogen peroxide biofuel cell that uses oxidase and peroxidase as catalysts by composite bulk-modified bioelectrodes based on a solid binding matrix

An improved composite bulk-modified bioelectrode setup based on a solid binding matrix (SBM) has been used to develop a glucose/hydrogen peroxide biofuel cell. Fuel is combined through a catalytically promoted reaction with oxygen into and oxidized species and electricity. The present work explores the feasibility of a sugar-feed biofuel cell based on SBM technology. The biofuel cell that utilizes mediators as electron transporters from the glucose oxidation pathway of the enzyme directly to electrodes is considered in this work. The anode was a glucose oxidase (GOx, EC 1.1.3.4)/ferrocene-modified SBM/graphite composite electrode. The cathode was a horseradish peroxidase (HRP, EC 1.11.1.7)/ferrocene-modified SBM/graphite composite electrode. The composite transducer material was layered on a wide polymeric surface to obtain the biomodified electrodic elements, anodes and cathodes and were assembled into a biofuel cell using glucose and H(2)O(2) as the fuel substrate and the oxidizer. The electrochemical properties and the characteristics of single composite bioelectrodes are described. The open-circuit voltage of the cell was 0.22 V, and the power output of the cell was 0.15 microW/cm(2) at 0.021 V. The biofuel cell proved to be stable for an extended period of continuous work (30 days). The reproducibility of the biotransducers fabrication was also investigated. In addition, an application of presented biofuel cell, e.g. the use of hydrolyzed corn syrup as renewable biofuels, was discussed.