LiFePO4 with an ordered olivine structure has been recognized as a promising cathode material for advanced Li-ion batteries due to its excellent thermal and structural stability, low cost of starting materials, high reversibility of Li ion insertionextraction, and non-toxicity . However, its practical application has suffered from the inherently poor kinetic properties caused by the low electro...

A composite of modified graphene and LiFePO4 has been developed to improve the speed of charging-discharging and the cycling stability of lithium ion batteries using LiFePO4 as a cathode material. Chemically activated graphene (CA-graphene) has been successfully synthesized via activation by KOH. The as-prepared CA-graphene was mixed with LiFePO4 to prepare the composite. Microscopic observatio...

LiFePO4 nanocrystals were synthesized at a very low temperature of 170°C using carbon nanoparticles by a solvothermal process in a polyol medium, namely diethylene glycol without any heat treatment as a post procedure. The powder X-ray diffraction pattern of the LiFePO4 was indexed well to a pure orthorhombic system of olivine structure (space group: Pnma) with no undesirable impurities. The Li...

Utilization of LiFePO4 as a cathode material for Li-ion batteries often requires size nanonization coupled with calcination-based carbon coating to improve its electrochemical performance, which, however, is usually at the expense of tap density and may be environmentally problematic. Here we report the utilization of micron-sized LiFePO4, which has a higher tap density than its nano-sized sibl...

ENHANCEMENT IN ELECTROCHEMICAL PERFORMANCE OF LiFePO4-CARBONNANO COMPOSITE MATERIALS FOR LITHIUM ION BATTERIESbyKULWINDER S. DHINDSAMay 2015Advisor:Dr. Zhixian ZhouCo Advisors: Dr. Ratna Naik and Dr. Gholam-Abbas NazriMajor:Physics (Condensed Matter)Degree:Doctor of PhilosophyLiFePO4 has attracted great interest as a cathode material for lithi...

The high-rate, high-capacity potential of LiFePO4-based lithium-ion battery cathodes has motivated numerous experimental and theoretical studies aiming to realize such performance through nano-sizing, tailoring of particle shape through synthesis conditions, and doping. Here, a granular mechanics study of microstructures formed by dense jammed packings of experimentally and theoretically inspir...

The Li+ ion diffusion coefficient of lithium iron phosphate LiFePO4 cathode materials should not be measured by the standard method because there is no composition variation but the movement of the LiFePO4/FePO4 interface during Li insertion/ extraction. A method to measure the intrinsic electronic and ionic conductivity of mixed conductive LiFePO4 was reported, for the first time, based on the...

Hierarchically structured LiFePO4 was successfully synthesized by ionic liquid solvothermal method. These hierarchically structured LiFePO4 samples were constructed from nanostructured platelets with their (010) facets mainly exposed. To the best of our knowledge, facet control of a hierarchical LiFePO4 crystal has not been reported yet. Based on a series of experimental results, a tentative me...

In this study, LiFePO4/C is synthesized via a novel two-step method. The first step is the synthesis of nano-sized intermediate FePO4 by a modified sol–gel method. A fast and full combustion procedure is involved to remove carbon and control the size of the intermediate particles. The second step is to prepare LiFePO4/C by combining solid-state reaction with controllable carbon coating. This tw...

Nano-sized and micron-sized LiFePO4 electrode materials were prepared by a sol gel and coprecipitation reactions. An improvement of the cycling and rate performances in lithium cells was observed for the carbon coated LiFePO4 materials. The coating process uses a solid/gas-phase reaction which consists of decomposing propylene gas, as carbon source, inside a reactor containing olivine LiFePO4 m...