再充電可能なリチウム-O2電池のアルキル炭酸電解質との反応

Stefan A Freunberger¹, Yuhui Chen, Zhangquan Peng

¹School of Chemistry, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK.

Journal of the American Chemical Society

|April 29, 2011

まとめ

非水性リチウムO2電池は,放電と充電の間にアルキル炭酸電解質を分解し,容量減少を引き起こす固体製品を形成します. この電解質分解は,これらの先進的なエネルギー貯蔵システムのサイクル寿命を制限します.

科学分野:

電気化学電気化学について
マテリアルサイエンス材料科学
エネルギー貯蔵エネルギー貯蔵

背景:

非水性充電式リチウムO2電池は,理論的に高いエネルギー密度を提供します.
電解質の分解は,その実用的な応用とサイクル寿命を制限する大きな課題です.

研究の目的:

Li-O(2) 細胞の充電と放電サイクル中の電解質分解の特定のメカニズムを解明する.
形成された化学物質の種類と,その影響がバッテリーの性能に及ぼす影響を特定するために.

主な方法:

放電中に形成されたカソド産物の分析.
サイクル中のアノド表面の変化の調査.
充電と放電過程の反応機構を提案する.

主要な成果:

排出形態は,カトドでC(3)H(6)(OCO(2)Li)(2),Li(2)CO(3),HCO(2)Li,CH(3)CO(2)Li,CO(2),およびH(2)Oとなっている.
充電には,これらの種がCO2とH2Oの進化によって酸化することが含まれます.
電解質の分解は,固体産物の蓄積,陽極上のゲル形成,容量の衰退,細胞の故障につながる.

結論:

提案された反応機構は,Li-O(2) 細胞における観測された電圧のギャップを説明する.
継続的な電解質消費と製品蓄積は,容量減少と限られたサイクル寿命の主要な原因です.
電解質の安定性を扱うことは,実用的なLi-O(2) バッテリーの開発に不可欠です.

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