Highly ordered LiFePO4 cathode material for Li-ion batteries templated by surfactant-modified polystyrene colloidal crystals

Yim, Chae-Ho; Baranova, Elena A.; Abu-Lebdeh, Yaser; Davidson, Isobel

doi:10.1016/j.jpowsour.2012.01.042

Cited by 36 publications

(14 citation statements)

References 31 publications

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“…LFP/CMT‐650 and LFP/CMT‐750 showed 12.4% and 7.8% weight loss, which is corresponding to carbon weight loss and Fe oxidation weight gain. Based on the weight gain in commercial LFP is 4 wt%, so 16.4 and 11.8 wt% carbon content were in LFP/CMT‐650 and LFP/CMT‐750, respectively. The carbon content in LFP/CMT‐850 is even not enough to surpass the increased quantity of oxidation of Fe 2+ ions in LFP.…”

Section: Methodsmentioning

confidence: 99%

Suppressing Fe–Li Antisite Defects in LiFePO₄/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

Zou

Chen

Yang

et al. 2016

Advanced Energy Materials

123

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ethanol) were found to play an important role in reducing the concentration of Fe-Li antisite defects. However, the concentration of Fe-Li antisite defects reduced is still limited (higher than 0.99%), which cannot improve the rate performance of LIB efficiently. [9,10] Herein, we report on the synthesis of an ideal crystalline LFP/carbon hybrid microtube (LFP/CMT) with the lowest Fe-Li antisite defects reported (<0.3%) to boost the lithium ion storage. The key concept for suppressing the Fe-Li antisite defects is through the use of the strong chelation interaction with Fe 3+ and absorbs interaction with Li + of alginate. This is able to efficiently control the prior occupancy of Fe at the beginning of the crystal formation, thus reduce the concentration of Fe-Li antisite defects in subsequent pyrolysis process and produce well-crystallized LFP nanoparticles (NPs). Meantime, the carbohydrate framework of alginate fiber was converted to highly porous carbonaceous hybrid microtube (CMT) after pyrolysis in nitrogen (N 2 ) atmosphere, in which the LFP NPs with low Fe-Li antisite defects are embedded. This can highly enhance the electrical conductivity of the LFP NPs. As a consequence, the LFP/CMT displays superior discharge capacity of 165 mAh g −1 at 0.5 C, excellent capacity retention of 91% after 1000 cycle numbers, and outstanding rate capacity of 99.7 mAh g −1 at 100 C.Protonated alginate fiber [11][12][13] was used to prepare the LFP electrodes with low Fe-Li antisite defects (see details in Supporting Information). The protonated alginate fiber was soaked into the mixed aqueous solutions of ferric nitrate nonahydrate (Fe(NO 3 ) 3 ·9H 2 O), ammonium dihydrogen phosphate (NH 4 H 2 PO 4 ), and lithium nitrate (LiNO 3 ) to form yellow Li-Fe-P-alginate fibers. The reduction of Fe-Li antisite defects is achieved by unique "egg-box" structure in alginate macromolecule. As shown in Scheme 1b, the Fe 3+ was immobilized into "egg-box" via coordination with G blocks in alginate, and the PO 4 3− was adsorbed by the Fe 3+ cations. As described in Figure S1 of the Supporting Information, the diffraction peak at 2θ = 21.18° was observed from the X-ray diffraction (XRD) pattern of Fe-P-alginate fiber, ascribed to a typical "egg-box" structure in G-rich Fe-alginate junction zones. [14,15] However, the monovalent Li + ions can only be adsorbed by the carboxyl (M block) via the electrostatic force. [16,17] The diffraction peaks at 2θ = 38.05° and 44.22° are ascribed to Fe-rich Li-alginate junction zones (see Figure S1, Supporting Information). [16] Obviously, the unexpected Fe-Li mixing could be avoided at the initial ion-exchange stage.The Li-Fe-P-alginate fibers were calcined at different temperatures (350-850 °C) in N 2 atmosphere to obtain a series of porous LFP/CMT with low concentration of Fe-Li antisite Olive structured LiFePO 4 (LFP) is a good candidate for lithiumion battery (LIB) cathode material due to its high theoretical capacity of 170 mAh g −1 , high electrochemical potential, good thermal stability, environmenta...

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Section: Methodsmentioning

confidence: 99%

Suppressing Fe–Li Antisite Defects in LiFePO₄/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

Zou

Chen

Yang

et al. 2016

Advanced Energy Materials

123

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“…The TGA curve LiFePO 4 shows a small increase in mass at 300 °C which is attributed to the Fe 2+ oxidation in air and it can be represented by Equation 1 29,30 . (1) In the TGA curve of PAni was observed three stages of weight loss below 850 °C.…”

Section: Thermal Characterization By Tgamentioning

confidence: 99%

PAni-coated LiFePO4 Synthesized by a Low Temperature Solvothermal Method

et al. 2018

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The composite LiFePO 4 /polyaniline was prepared by chemical synthesis to promote the intensification of the electrochemical properties for use as cathodes in lithium ion batteries. The X-ray diffraction (XRD) of LiFePO 4 synthesized by solvothermal method were indexed to the orthorhombic structure, according to the JCPDS 40-1499. The spectra Raman and FTIR showed a high degree of ordering of LiFePO 4 with interaction between LiFePO 4 surface with structure conjugate of conducting polymers. The cyclic voltammogram of the composite synthesized chemically showed a significant reduction in the value of ΔE p (ΔE p = 0.20 V) when compared to LiFePO 4 (ΔE p = 0.41 V), with lower charge transfer resistance values, indicating favoring electron transfer rate in the composite. Thus, the alternative synthesis route of the LiFePO 4 / PAni composite was easy to handle and allowed an increase in the electrochemical properties of the LiFePO 4 , compared to the traditional methods that require additional thermal treatments.

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“…Further, a feable weight increment of 0.08 % is due to the oxidation of LiFePO 4 . Finally, the prepared materials calcined above 900°C are observed the weight loss of 2.90 % which is attributed to presence of carbon in prepared sample [26]. The higher oxidation is presumably due to larger crystallite size of LiFePO 4 and small amount distribution of carbons.…”

Section: Resultsmentioning

confidence: 89%

A facile synthesis and characterization of LiFePO4/C using simple binary reactants with oxalic acid by polyol technique and other high temperature methods

Muruganantham

Sivakumar

2015

J Mater Sci: Mater Electron

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An attempt has been made to synthesize the carbon coated Fe-based phospho-olivine nano-crystalline cathode materials using simple binary sources via polyol method. Also, a curious attempt has been made to compare the material with the high temperature methods, viz., hydrothermal and solid state method with the same binary sources as raw materials and oxalic acid as a carbon source. The thermal behaviour of the mixed raw materials of LiFePO 4 and thermal stability of the final prepared materials were characterized by TGA. The prepared materials were confirmed as orthorhombic olivine structure with Pnma space group. LiFePO 4 /C material prepared by Polyol method exhibits an initial reverse capacity of 150 mAh g -1 at 0.1 C rate under room temperature. Also, stable capacity of 143 mAh g -1 has been observed over 50 cycles at 0.1 C rate at room temperature among the other methods studied. It may be due to the coverage of tiny particles by carbon and it leads to provide better electronic conductivity and thereby provides good electrochemical performances.

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Highly ordered LiFePO4 cathode material for Li-ion batteries templated by surfactant-modified polystyrene colloidal crystals

Cited by 36 publications

References 31 publications

Suppressing Fe–Li Antisite Defects in LiFePO₄/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

Suppressing Fe–Li Antisite Defects in LiFePO₄/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

PAni-coated LiFePO4 Synthesized by a Low Temperature Solvothermal Method

A facile synthesis and characterization of LiFePO4/C using simple binary reactants with oxalic acid by polyol technique and other high temperature methods

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Highly ordered LiFePO4 cathode material for Li-ion batteries templated by surfactant-modified polystyrene colloidal crystals

Cited by 36 publications

References 31 publications

Suppressing Fe–Li Antisite Defects in LiFePO4/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

Suppressing Fe–Li Antisite Defects in LiFePO4/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

PAni-coated LiFePO4 Synthesized by a Low Temperature Solvothermal Method

A facile synthesis and characterization of LiFePO4/C using simple binary reactants with oxalic acid by polyol technique and other high temperature methods

Contact Info

Product

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About

Suppressing Fe–Li Antisite Defects in LiFePO₄/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage

Suppressing Fe–Li Antisite Defects in LiFePO₄/Carbon Hybrid Microtube to Enhance the Lithium Ion Storage