A New Synthetic Route for Preparing LiFePO[sub 4] with Enhanced Electrochemical Performance

Abstract

Nanocrystalline LiFePO4 was obtained by heating amorphous nanosized LiFePO4. The amorphous material was obtained by lithiation of FePO4 synthesized by spontaneous precipitation from equimolar aqueous solutions of normalFefalse(NH4)2false(SO4)2⋅6H2O and NH4H2PO4, using hydrogen peroxide as the oxidizing agent. The materials were characterized by chemical analysis, thermogravimetric and differential thermal analysis, X-ray powder diffraction, and scanning electron microscopy. The Brunauer- Emmett-Teller method was used to evaluate the specific surface area. Nanocrystalline LiFePO4 showed very good electrochemical performance delivering about the full theoretical capacity false(170 Ah kg−1false) when cycled at the C/10 rate. A capacity fade of about 0.25% per cycle affected the material upon cycling. © 2002 The Electrochemical Society. All rights reserved.

Vanadium Substitution of LiFePO4 Cathode Materials To Enhance the Capacity of LiFePO4-Based Lithium-Ion Batteries

“…1,2 The electronic conductivity can be improved by coating a layer of carbon 3,4 and by adding transition metals. 5−10 In addition, the Li + ion diffusion rate and the amount of lithium extracted from LiFePO 4 can be manipulated by synthesizing nanometer grain sizes, 10,11 as well as by adding transition metals. 12−14 Therefore, in this work, to maximize electronic conductivity, minimize Li + ion diffusion lengths, maximize Li + ion diffusion rates in LiFePO 4 particles, the addition of transition metals to nanometer-sized LiFePO 4 is the most viable method.…”

Optimized LiFePO4–Polyacene Cathode Material for Lithium‐Ion Batteries

“…Fortunately, low electronic conductivity can be successfully overcome by such methods as modifying the LiFePO 4 particles with carbon [10][11][12][13][14] and also by minimizing particle size. [15,16] These structures either adopted an sp 3 character for carbon or they formed linear polymers with an sp 2 character on the carbon atoms in the chain. This category of carbon seriously impacts the electrochemical performance of LiFePO 4 .…”

Enhanced cycling performance and high energy density of LiFePO4 based lithium ion batteries

“…4 , the scan rate was 250 mA, the type of battery is 063048 and (b) charge/discharge cycle properties of LiFePO 4 , the charge scan rate was 1000 mA, the discharge scan rate was 5000 mA, the type of battery is 18650. …”

“…The important factors governing their applications are low price, long cycle life, environment friendliness, safety, and high specific energy density. Orthorhombic LiFePO 4 which has an ordered olivine structure has attracted particular interest because it is environmentally benign, inexpensive and abundant in its raw materials [1]. However, LiFePO 4 has a poor rate capability attributed to low electronic conductivity which has hampered its applications as cathode materials in lithium ion batteries.…”