高等学校化学学报
高等學校化學學報
고등학교화학학보
Chemical Journal of Chinese Universities
2015年
9期
1771-1778
,共8页
潘文博%李明雪%苏亚琼%吴德印%田中群
潘文博%李明雪%囌亞瓊%吳德印%田中群
반문박%리명설%소아경%오덕인%전중군
锂硫电池%密度泛函理论%拉曼光谱%碳酸乙烯酯%多硫阴离子
鋰硫電池%密度汎函理論%拉曼光譜%碳痠乙烯酯%多硫陰離子
리류전지%밀도범함이론%랍만광보%탄산을희지%다류음리자
Lithium sulfur battery%Density functional theory%Raman spectroscopy%Ethylene carbonate%Polysulfide
通过密度泛函理论( DFT)计算了锂硫电池中多硫阴离子( S2-n )和碳酸乙烯酯( EC)的2种反应机理,并对其反应物和主要产物的拉曼光谱进行了理论分析。计算结果表明,2种反应路径中, S2-n 进攻EC分子烷基碳所需活化能和Gibbs自由能均较低。多硫基团有很强的拉曼特征谱峰,与EC分子相关的部分拉曼谱亦发生显著变化。锂离子的存在影响反应产物的结构和拉曼光谱。密度泛函理论计算提供了锂硫电池中锂、多硫阴离子和电解液反应前后的结构变化和反应信息。
通過密度汎函理論( DFT)計算瞭鋰硫電池中多硫陰離子( S2-n )和碳痠乙烯酯( EC)的2種反應機理,併對其反應物和主要產物的拉曼光譜進行瞭理論分析。計算結果錶明,2種反應路徑中, S2-n 進攻EC分子烷基碳所需活化能和Gibbs自由能均較低。多硫基糰有很彊的拉曼特徵譜峰,與EC分子相關的部分拉曼譜亦髮生顯著變化。鋰離子的存在影響反應產物的結構和拉曼光譜。密度汎函理論計算提供瞭鋰硫電池中鋰、多硫陰離子和電解液反應前後的結構變化和反應信息。
통과밀도범함이론( DFT)계산료리류전지중다류음리자( S2-n )화탄산을희지( EC)적2충반응궤리,병대기반응물화주요산물적랍만광보진행료이론분석。계산결과표명,2충반응로경중, S2-n 진공EC분자완기탄소수활화능화Gibbs자유능균교저。다류기단유흔강적랍만특정보봉,여EC분자상관적부분랍만보역발생현저변화。리리자적존재영향반응산물적결구화랍만광보。밀도범함이론계산제공료리류전지중리、다류음리자화전해액반응전후적결구변화화반응신식。
Two mechanisms of the reaction between polysulfides(S2-n , n=2—4) and ethylene carbonate(EC) and Raman spectra of the reactants and main products were investigated by density functional theory(DFT) method. The results showed that the reaction of polysulfides attacking the ethyl carbon of EC is more favorable than that attacking the carbonyl carbon of EC in terms of the activation energies and Gibbs free energies. Sulfur groups in polysulfides display strong Raman signals, so that simulated Raman spectra of the products of the S2-n +EC reaction significantly change after the reaction. The coordination effect of Li+ cation also influenced the simulated Raman spectra of reaction products. DFT results and Raman spectroscopic analysis provide a new insight on structural stability of polysulfides and EC electrolyte in the lithium sulfur battery.