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| Type |
Oral Presentation |
| Area |
Oral Presentation for Young Material Chemists |
| Room No. |
Room 303 (Live Streaming) |
| Time |
TUE 09:00-09:15 |
| Code |
MAT.O-1 |
| Subject |
Ammonium Vanadium Bronze as a Cathode Material for Nonaqueous Calcium-Ion Batteries |
| Authors |
Hyeri Bu, Seung-Tae Hong*
ENERGY SCIENCE AND ENGINEERING, Daegu Gyeongbuk Institute of Science & Technology, Korea
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| Abstract |
Calcium-ion batteries(CIBs) are considered an attractive candidate for post Li-ion batteries. However, there are few cathode materials which intercalate Ca ions reversibly in nonaqueous electrolyte. Herein, we discover a novel ammonium vanadium bronze, NVO, as a host material of CIBs. NVO has been synthesized via a facile hydrothermal method. The structure(P-1) is determined from a single-crystal X-ray diffraction (XRD) data for the first time. It has a layered structure similar to other vanadium bronzes but with an unprecedented stoichiometry and crystal structure. The structure is composed of V-O layers stacking along the c-axis and two NH4+ ions occupying the interlayer space per formula unit. A reversible electrochemical intercalation of Ca2+ ions into NVO has been demonstrated using galvanostatic discharge/charge cycling. The discharge capacities are ~98 and 87 mAh g-1 for the first and second cycles, respectively. On charge, ion-exchange reaction is happened, while a small amount of Ca2+ ions are intercalated while the NH4+ ions are de-intercalated. On discharge, Ca2+ ions are inserted and simultaneously some fraction of the extracted ammonium ions are reinserted. Small amounts of reinserted ammonium ions play an important role in structural stability, enabling better cycle performance. Understanding the newly discovered mechanism of this material is expected to provide general insights into ammonium vanadium bronze as the anode material. |
| E-mail |
qngpfl@dgist.ac.kr |
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125th General Meeting of the KCS