title: Fast-Rate Capable Electrode Material with Higher Energy Density than LiFePO4: 4.2V LiVPO4F Synthesized by Scalable Single-Step Solid-State Reaction.
abstract: 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 LiVPO4F. The resulting material with submicron particles achieves very high rate capability ≈100 mAh g-1at 60 C-rate (1-min discharge) and even at 200 C-rate (18 s discharge). It retains superior capacity, ≈120 mAh g-1at 10 C charge/10 C discharge rate (6-min) for 500 cycles with >95% retention efficiency. Furthermore, LiVPO4F 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 LiVPO4F can achieve high power capability comparable to LiFePO4and much higher energy density (≈521 Wh g-1at 20 C-rate) than LiFePO4even without nanostructured particles. LiVPO4F can be a real substitute of LiFePO4.
authors: Department of Materials Science and Engineering Pohang University of Science and Technology (POSTECH) Pohang 790-784 Republic of Korea.
authors: Minkyung
authors: M
authors: Kim
authors: Korea Atomic Energy Research Institute P.O. Box 105 Yuseong-gu Daejeon 305-600 Republic of Korea.
authors: Seongsu
authors: S
authors: Lee
authors: Department of Materials Science and Engineering Pohang University of Science and Technology (POSTECH) Pohang 790-784 Republic of Korea.
authors: Byoungwoo
authors: B
authors: Kang
keywords: F‐containing compounds; LiVPO4F; PTFE as additional fluorine source; high power material; lithium ion batteries