کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
184857 | 459582 | 2015 | 8 صفحه PDF | دانلود رایگان |

• Thiophene derivatives (THs) can serve as novel electrolyte additives for LIBs.
• THs tend to be electro-polymerized on LiCoO2 cathode prior to the solvents.
• A conducting polymer film can be formed using THs additives in the electrolyte.
• The cycling stability of high voltage LiCoO2 is obviously improved using additives.
Thiophene derivatives (THs) are examined as novel functional additives for improving the cycling performance of high-voltage LiCoO2. Our investigation reveals that 2,2′-Bithiophene (2TH) and 2,2′:5′,2′′-Terthiophene (3TH) can be electrochemically polymerize prior to the electrolyte solvent decomposition to form a protective layer of conducting polymer film on the cathode surface, which blocks off severe electrolyte decomposition at high voltages and, therefore, improves the cycling stability of high voltage LiCoO2 cathode. After 100 cycles at a high cutoff voltage of 4.4 V, the discharge capacity retention is 50% in the base electrolyte, in contrast, the LiCoO2 cathode cycled in the electrolyte containing 0.1 wt% 3TH displays a high capacity retention of 84.8% at 0.25 C rate. This work demonstrates that these thiophene derivatives have considerable potential as functional additives for the applications in high-voltage lithium-ion batteries.
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Journal: Electrochimica Acta - Volume 151, 1 January 2015, Pages 429–436