Open AccessFast‐Rate Capable Electrode Material with Higher Energy Density than LiFePO 4 : 4.2V LiVPO 4 F Synthesized by Scalable Single‐Step Solid‐State Reaction
Author(s) -
Kim Minkyung,
Lee Seongsu,
Kang Byoungwoo
Publication year - 2016
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201500366
Subject(s) - materials science , electrode , lithium (medication) , fluorine , power density , energy density , ion , analytical chemistry (journal) , solid state , chemical engineering , chemistry , power (physics) , thermodynamics , metallurgy , chromatography , organic chemistry , engineering physics , medicine , physics , engineering , endocrinology
Use of compounds that contain fluorine (F) as electrode materials in lithium ion batteries has been considered, but synthesizing single‐phase samples of these compounds is a difficult task. Here, it is demonstrated that a simple scalable single‐step solid‐state process with additional fluorine source can obtain highly pure LiVPO 4 F. The resulting material with submicron particles achieves very high rate capability ≈100 mAh g −1 at 60 C‐rate (1‐min discharge) and even at 200 C‐rate (18 s discharge). It retains superior capacity, ≈120 mAh g −1 at 10 C charge/10 C discharge rate (6‐min) for 500 cycles with >95% retention efficiency. Furthermore, LiVPO 4 F shows low polarization even at high rates leading to higher operating potential >3.45 V (≈3.6 V at 60 C‐rate), so it achieves high energy density. It is demonstrated for the first time that highly pure LiVPO 4 F can achieve high power capability comparable to LiFePO 4 and much higher energy density (≈521 Wh g −1 at 20 C‐rate) than LiFePO 4 even without nanostructured particles. LiVPO 4 F can be a real substitute of LiFePO 4.