Lithium Superionic Conducting Oxysulfide Solid Electrolyte with Excellent Stability against Lithium Metal for All-Solid-State Cells. Issue 2 (9th November 2015)

• Record Type: Journal Article
• Authors: Tao, Yicheng; Chen, Shaojie; Liu, Deng; Peng, Gang; Yao, Xiayin; Xu, Xiaoxiong
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 2(2016)
• Page Start: A96
• Page End: A101
• Publication Date: 2015-11-09
• Subjects: 75Li2S25P2S5 solid electrolyte -- All-solid-state cell -- Lithium ion conductivity -- P2O5 dopant -- Stability against lithium metal; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0311602jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : For the high-energy battery using Li metal as a negative electrode, the electrolyte is one of the most critical factors that significantly affects the cell performance. Herein, new 75Li2 S·(25- x )P2 S5 · x P2 O5 (mol%) solid state electrolytes are prepared by optimized mechanical milling technique and subsequent heat-treatment process. The electrolyte substituted with 1 mol% P2 O5 presents the highest conductivity of 8 × 10 −4 S cm −1 at room temperature, which increases up to 56% compared to that of the pristine sample. The enhanced conductivity could be attributed to the decrease of the activation energy for Li + -ion diffusion. The as-prepared 75Li2 S·24P2 S5 ·1P2 O5 electrolyte exhibits good electrochemical stability and compatibility with the metallic lithium electrode. The all-solid-state cell with a structure of LiCoO2 /75Li2 S·24P2 S5 ·1P2 O5 /Li shows a discharge capacity of 109 mAh g −1 at 0.1 C and high capacity retention 85.2% after 30 cycles at 25°C, which are better than these of the cell use the 75Li2 S·25P2 S5 as electrolyte.