TITLE:
Phosphorus Based Ceramics for Positive Electrode Synthesis and Characterization
AUTHORS:
Diouma Kobor, Abdou Kadri Diallo, Modou Tine
KEYWORDS:
Characterization, X-Ray Diffraction, EDX, Ceramic, Positive Electrode
JOURNAL NAME:
Journal of Modern Physics,
Vol.5 No.15,
September
26,
2014
ABSTRACT: Historically,
the LiCoO2 is the most used as active material for battery positive
electrode because of its great potential (3.7 - 4.2 V), its interesting
specific capacity (150 mA·h·g-1) and its excellent life cycle [1]
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. However, its toxicity, the cobalt cost and its structural instability
oriented research towards new materials more stable that can replace it. In
another context, hybrid, electrical vehicles and communication (computers and
mobile phones...) have increased the scientific and technological research for
new materials capable of storing and return energy through a system called
accumulator. And research has identified the phosphate olivine structure as the
most prolific ceramic material for positive electrode. LiFePO4 is a
promising cathode material for Lithium-ion batteries. It provides high thermal
stability and is synthesized using low cost materials. Unfortunately LiFePO4 suffers from a low electrical conductivity, which is harmful to its
electrochemical performance. Decreasing the particle size, coating the particles
with carbon or doping with metal atoms can increase the conductivity of the
material. In this paper, we present the synthesis, physico-chemical and
electrical characterization of lithium and iron doped Al-phosphorrus-based
ceramic. The NPK Fertiliser was used as Al and phosphorus precursors. The powder
XRD spectrum shows a possible presence of LiFePO4 and Fe2(PO)3 in theheterostrcture. An
important quantity of Al is found by EDX spectra which supposed that the most
important based atom is Aluminum and not Phosphorus. This can explain the
increase of the conductivity value 102 times more important than those
found in the literature for LiFePO4.