• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Development of electrode materials for electrochemical capacitors.
【24h】

Development of electrode materials for electrochemical capacitors.

机译：电化学电容器用电极材料的开发。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Electrochemical capacitors (ECs) are charge storage devices. ECs have higher power density than batteries and higher energy density than dielectric capacitors. ECs are classified as electrochemical double layer capacitors (EDLCs) and pseudocapaeitors based on the charge storage mechanism. The present research deals with development of electrode materials for both categories of ECs.; The manganese oxide based electrodes MnO2, stabilized MnO 2, Co stabilized MnO2 and V2O5 are developed as electrode materials for pseudocapaeitors. These oxides are prepared using a sol-gel method, and characterized using TGA, XRD, SEM and BET. Charge storage characteristics of these electrode materials are evaluated using a cyclic voltammetric technique utilizing a three electrode method in neutral electrolytes. MnO2 electrode showed ideal capacitive characteristics with the highest capacitance 145 F/g in 1M NaCl electrolyte but the capacitance quickly faded. This was circumvented by preparing MnO2 in a stable form and by doping 15 atomic % Co into the MnO2 lattice. Both of these materials showed constant capacitance up to 800 cycles. A highly porous V2O5 showed promising capacitive characteristics with capacitance of 214 F/g but the capacitance faded within 100 cycles.; In EDLC, carbon materials derived from catechol-formaldehyde (CF) carbon precursors are developed as electrode materials. CF gels are synthesized using a sol-gel method at various pH conditions and carbon is produced by decomposing them at 750° C. Thus obtained carbon is electrochemically characterized using a cyclic voltammetric technique in 30 wt% H2SO4 electrolyte. Carbon prepared from precursor synthesized at pH 6 yielded the highest capacitance of 109 F/g. A single cell EDLC is fabricated employing carbon prepared CF gel, and is tested using constant current charge-discharge method.; An analytical solution for the voltage distribution in one-dimensional porous electrode subjected to cyclic voltammetric conditions was developed. This analytical solution was employed in deriving the charging currents. Using charging currents equivalent series resistances of carbons derived from catechol-formaldehyde gels prepared at pH conditions of 3, 6, 7.5 in 30 wt% H2SO 4 electrolyte were deduced. The model derived resistance values match exactly with resistance value obtained from galvanostatic constant current charge-discharge method.
机译：电化学电容器（EC）是电荷存储设备。 EC具有比电池更高的功率密度和比介电电容器更高的能量密度。根据电荷存储机制，EC分为电化学双层电容器（EDLC）和伪电容器。本研究涉及两种EC的电极材料的开发。锰氧化物电极MnO2，稳定的MnO2，Co稳定的MnO2和V2O5被开发为拟电容器的电极材料。这些氧化物使用溶胶-凝胶法制备，并使用TGA，XRD，SEM和BET进行表征。这些电极材料的电荷存储特性通过使用中性电解质中的三电极法的循环伏安技术进行评估。 MnO2电极表现出理想的电容特性，在1M NaCl电解质中的最高电容为145 F / g，但电容很快消失。通过以稳定的形式制备MnO2并将15原子％的Co掺杂到MnO2晶格中可以避免这种情况。这两种材料均显示出高达800次循环的恒定电容。高度多孔的V2O5表现出良好的电容特性，电容值为214 F / g，但电容在100个周期内衰减。在EDLC中，衍生自邻苯二酚-甲醛（CF）碳前体的碳材料被开发为电极材料。使用溶胶-凝胶法在各种pH条件下合成CF凝胶，并通过在750°C下分解生成碳。使用循环伏安技术在30 wt％的H2SO4电解质中对由此获得的碳进行电化学表征。由在pH 6下合成的前体制备的碳产生的最大电容为109 F / g。用碳制备的CF凝胶制备单电池EDLC，并使用恒流充放电方法进行测试。针对一维多孔电极在循环伏安条件下的电压分布，提出了一种解析方法。该分析解决方案用于推导充电电流。使用充电电流，推导了在30 wt％H2SO 4电解质中在3、6、7.5的pH条件下制备的邻苯二酚甲醛凝胶衍生的碳的等效串联电阻。模型导出的电阻值与通过恒电流恒流充放电法获得的电阻值完全匹配。

著录项

  • 作者

    Nagireddy, Ravinder Reddy.;

  • 作者单位

    The University of Alabama.;

  • 授予单位 The University of Alabama.;
  • 学科 Engineering Metallurgy.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 180 p.
  • 总页数 180
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 冶金工业;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号