储能科学与技术 ›› 2017, Vol. 6 ›› Issue (3): 493-499.doi: 10.12028/j.issn.2095-4239.2017.0022

• 特约文章 • 上一篇    下一篇

水系黏结剂琼脂在锂硫电池中的应用

唐  振，熊传溪   

  1. 武汉理工大学材料科学与工程学院，湖北 武汉 430070
  • 收稿日期:2017-03-08 修回日期:2017-03-14 出版日期:2017-05-01 发布日期:2017-05-01
  • 通讯作者: 熊传溪，教授，研究方向为储能材料，E-mail：cxiong@whut.edu.cn。
  • 作者简介:唐振（1991—），男，硕士研究生，研究方向为先进高分子材料，E-mail：zhentang@whut.edu.cn
  • 基金资助:
    国家自然科学基金项目（51673154，51503159）。

Agar as water soluble binder for lithium-sulfur battery

TANG Zhen, XIONG Chuanxi   

  1. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, Hubei, China
  • Received:2017-03-08 Revised:2017-03-14 Online:2017-05-01 Published:2017-05-01

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摘要：

水系黏结剂一般采用水作为溶剂，因其环境友好、成本低、使用安全等优点受到研究者的广泛关注。琼脂黏结剂在室温下几乎不溶于水导致正极浆料的配置无法进行，因此本工作采用H2O2作为氧化剂，将琼脂（AG）的羟基部分氧化成羧基，氧化后的琼脂（M-AG）在室温下易溶于水，并且羧基的存在对多硫化锂具有一定的吸附作用，在充放电过程中抑制了多硫化锂的“穿梭”，提高了锂硫电池的稳定性。将M-AG应用于锂硫电池黏结剂中具有很好的黏结性能，能够保持活性物质、导电剂和集流体之间良好的接触。电化学性能表明，M-AG不参与锂硫电池中的电化学反应，在充放电过程中能够保持电极结构的稳定。在0.1 C恒流充放电条件下，相对于传统的PVDF黏结剂，M-AG作为黏结剂时，具有更高的活性材料利用效率（首次放电比容量为700 mA·h/g）和容量保持率（100次循环后容量保持率高达90.7%）。

Abstract:

Water soluble binder has caused extensive concern because of its environmentally friendly, low cost and safety, etc. Cathode slurry can not be configured bacause the agar binder is almost insoluble in water at room temperature. The hydroxyl groups of agar (AG) were partially oxidized to carboxyl groups by H2O2. Oxidized agar (M-AG) can be easily dissolved in water at room temperature. The presence of carboxyl groups may adsorb lithium polysulfide, which inhibits the "shuttle" of lithium polysulfide during the charging and discharging process. In this work, the M-AG was used as binder in lithium-sulfur battery. The good contact among the active material, the conductive agent and the current collector can be well preserved with M-AG as binders. The M-AG does not participate the electrochemical reaction in lithium-sulfur battery. The structure of the electrode can be stabilized during the repeated charging and discharging process. The M-AG electrode has higher capacity release and capacity retention than the conventional PVDF electrode. It delivers an initial specific discharge capacity of 700 mA·h·g1 with a high capacity retention ratio of 90.7% after 100 cycles.