本文へジャンプ

成果報告書詳細
管理番号20170000000222
タイトル*平成28年度中間年報 革新型蓄電池実用化促進基盤技術開発(国立大学法人三重大学)
公開日2017/11/14
報告書年度2016 - 2016
委託先名国立大学法人三重大学
プロジェクト番号P16001
部署名スマートコミュニティ部
和文要約
英文要約Title: Research and Development Initiative for Scientific Innovation of New
Generation Batteries 2 (RISING2). Materials Development of Sulfide-based
Batteries (FY2016-FY2018) FY2016 Annual Report

In order to improve charge-discharge cycle performance of the metal sulfide cathode, the surface of the cathode must be protected from forming a passivation layer by unexpected side-reactions with a nonaqueous electrolyte. The surface was originally coated with polymer materials to avoid this passivation. In FY2016, preparation of several polymers were conducted and their protection effect was evaluated. We also examined electrolyte additives to form protective film by electrochemical decomposition.

(A) Evaluation of a model electrode
(1)Reproducibility of the cycle performance
The standard electrode provided by AIST, was tested in Mie University. A protocol for the electrode pretreatment was found critical in order to have a reproducible electrochemical electrode behavior. It was also confirmed that the standard electrolyte solution gives the best performance at present.
(2) Understanding the cause of deterioration
The standard electrode exhibits a very large irreversible capacity and undergoes degradation during cycles with the operation between 1 and 3 V. The performance was much improved by applying appropriate cut-off voltages. We additionally checked an influence of fluorine. Since fluorine has been detected on the electrode surface, we tested different types of electrolyte solutions with fluorine-free salts such as LiClO4. The result showed no improvement which suggests no influence of fluorine on the deterioration.

(B) Polymer coating on the electrode
(1) Preparation of cross-linked polymer for coating
Three kinds of polymer electrolytes were prepared; polyethylene oxide (PEO) -based polymers cross-linked by UV irradiation, cross-linked by heating, and with mechanically movable cross-linking. For the second type, cross-linking at 80 ° C for about 24 hours and at 130 ° C for about 2 hours gave a uniform film. The viscoelastic character varies by the degree of crosslinking and its optimization is underway. Coating is carried out after the optimization is completed.
Electron-conductive polymers were also synthesized to ensure conducting network around the active material. For these polymers the solvent tolerance was examined and preliminary casting on the electrode was conducted.
(2) Screening electrolyte additives
The effects of adding Lewis acid/base into electrolytes, and some chemical agents known as SEI former on positive electrode were examined for the standard electrode. As a result, one additive improved the cycle performance. Quantitative studies are being carried out to find the optimum amount for a better performance.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る