Abstract

First, nano-spherical iron phosphate was prepared using the hydrothermal method. Then, the carbothermal reduction method was applied to synthesize the LiFePO4/C composite material capable of good carbon coating effect with the prepared nano-spherical iron phosphate as a precursor. By means of scanning electron microscope, transmission electron microscope, Zeta potentiometer, inductively coupled plasma spectrometer, X-ray diffraction, X-ray photoelectron spectroscopy, electrochemical testing, and other methods, the material was characterized and tested for its morphology, particle size, composition, structure, and electrochemical performance. According to the test results, when the initial mass concentration of Fe3+ in the reaction solution is 2%, the amount of N and S impurity is merely 19 and 27 ppm, respectively. In the meantime, particle size is small, with a range of roughly 50–100 nm, and a spherical morphology is shown. The synthesized LiFePO4/C retains its nano-spherical morphology, which leads to a desirable carbon coating effect and an excellent electrochemical performance. The first charge–discharge specific capacity at 0.1 C rate reached 163.7 and 161.4 mAh/g, the charge–discharge efficiency was 98.6%, and the capacity retention rate at 50 charge–discharge cycles at 1 C rate reached 98.52%.

References

References
1.
Padhi
,
A. K.
,
Goodenough
,
J. B.
, and
Nanjundaswamy
,
K. S.
,
1997
, “
Phospho-Olivines as Positive-Electrode Materials for Rechargeable Lithium Batteries
,”
J. Chem. Soc.
,
144
, pp.
1188
1194
. 10.1149/1.1837571
2.
Shi
,
W.
,
Hu
,
X. S.
,
Jin
,
C.
,
Jiang
,
J. C.
,
Zhang
,
Y. R.
, and
Yip
,
T.
,
2016
, “
Effects of Imbalanced Current on Large-Format LiFePO4/Graphite Batteries Systems Connected in Parallel
,”
J. Power Sources
,
313
, pp.
198
204
. 10.1016/j.jpowsour.2016.02.087
3.
Chun
,
S. Y.
,
Blocking
,
J. T.
,
Anderson
,
A. S.
, and
Chiang
,
Y. M.
,
2015
, “
Electronically Conductive Phosphor-Olivines as Lithium Storage Electrodes
,”
Nat. Mater.
,
1
, pp.
121
123
.
4.
Cheng
,
W.
,
Wang
,
L.
, and
Sun
,
Z.
,
2017
, “
Preparation and Characterization of LiFePO4xLi3V2(PO4)3 Composites by Two-Step Solid-State Reaction Method for Lithium-Ion Batteries
,”
Mater. Lett.
,
198
, pp.
172
175
. 10.1016/j.matlet.2017.04.008
5.
Vicente
,
N.
,
Haro
,
M.
, and
Cintora-juarez
,
D.
,
2015
, “
LiFePO4 Particle Conductive Composite Strategies for Improving Cathode Rate Capability
,”
Electrochim. Acta
,
163
, pp.
323
329
. 10.1016/j.electacta.2015.02.148
6.
Yang
,
C. C.
,
Jang
,
J. H.
, and
Jiang
,
J. R.
,
2016
, “
Study of Electrochemical Performance of Lithium Titanium Oxide-Coated LiFePO4/C Cathode Composite at Low and High Temperatures
,”
Appl. Energy
,
162
, pp.
1419
1427
. 10.1016/j.apenergy.2015.01.131
7.
Bazzi
,
K.
,
Nazri
,
M.
,
Naik
,
V. M.
,
Garg
,
V. K.
,
Oliveir
,
A. C.
,
Vaishnav
,
P. P.
,
Nazri
,
G. A.
, and
Naika
,
R.
,
2016
, “
Enhancement of Electrochemical Behavior of Nanostructured LiFePO4/Carbon Cathode Material With Excess Li
,”
J. Power Sources
,
306
, pp.
17
23
. 10.1016/j.jpowsour.2015.11.086
8.
Wang
,
T.
,
Wang
,
Y.
,
Wu
,
Y. N.
,
Zhou
,
L.
,
Jin
,
Y.
,
Liu
,
W. M.
,
Huang
,
J.
,
Fang
,
X.
, and
Tang
,
X. C.
,
2017
, “
LiFePO4/C Composite Prepared by Coal Based Carbon Sources
,”
Int. J. Electrochem. Sci.
,
12
, pp.
975
984
. 10.20964/2017.02.19
9.
Zhang
,
Y. T.
,
Xin
,
P. Y.
, and
Yao
,
Q. F.
,
2018
, “
Electrochemical Performance of LiFePO4/C Synthesized by Sol-Gel Method as Cathode for Aqueous Lithium Ion Batteries
,”
J. Alloys Compd.
,
741
, pp.
404
408
. 10.1016/j.jallcom.2018.01.083
10.
Ma
,
X. J.
,
Gai
,
L. G.
, and
Tian
,
Y.
,
2018
, “
Hierarchically Structured LiFePO4/C With Enhanced Electrochemical Performance for Lithium-Ion Batteries
,”
Int. J. Electrochem. Sci.
,
13
, pp.
1376
1389
. 10.20964/2018.02.36
11.
Li
,
X.
,
Jiang
,
Y. Z.
,
Li
,
X. K.
,
Jiang
,
H. X.
,
Liu
,
J. L.
,
Feng
,
J.
,
Lin
,
S. B.
, and
Guan
,
X.
,
2018
, “
Electrochemical Property of LiFePO4/C Composite Cathode With Different Carbon Sources
,”
Rare Met.
,
37
(
9
), pp.
743
749
. 10.1007/s12598-016-0781-9
12.
Scipioni
,
R.
,
Jørgensen
,
P. S.
,
Ngo
,
D. T.
,
Simonsen
,
S. B.
,
Liu
,
Z.
,
Kremski
,
K. J. Y.
,
Wang
,
H. Q.
,
Hjelm
,
J.
,
Norby
,
P.
,
Barnett
,
S. A.
, and
Jensen
,
S. H.
,
2016
, “
Electron Microscopy Investigations of Changes in Morphology and Conductivity of LiFePO4/C Electrodes
,”
J. Power Sources
,
307
, pp.
259
269
. 10.1016/j.jpowsour.2015.12.119
13.
Yang
,
C. C.
,
Jang
,
J. H.
, and
Jiang
,
J. R.
,
2014
, “
Comparison Electrochemical Performances of Spherical LiFePO4/C Cathode Materials at Low and High Temperatures
,”
Energy Procedia
,
61
, pp.
1402
1409
. 10.1016/j.egypro.2014.12.136
14.
Zeng
,
X. Y.
,
Liu
,
Q. B.
,
Chen
,
M. F.
,
Ting
,
L. L.
,
Du
,
S. L.
,
Song
,
H. Y.
, and
Liao
,
S. J.
,
2015
, “
Electrochemical Behavior of Spherical LiFePO4/C Nanomaterial in Aqueous Electrolyte, and Novel Aqueous Rechargeable Lithium Battery With LiFePO4/C Anode
,”
Electrochim. Acta
,
177
, pp.
277
282
. 10.1016/j.electacta.2014.12.088
15.
Zhao
,
N. N.
,
Li
,
Y. S.
,
Zhao
,
X. X.
,
Zhi
,
X. K.
, and
Liang
,
G. C.
,
2016
, “
Effect of Particle Size and Purity on the Low Temperature Electrochemical Performance of LiFePO4/C Cathode Material
,”
J. Alloys Compd.
,
683
, pp.
123
132
. 10.1016/j.jallcom.2016.04.070
16.
Liu
,
Y.
,
Zhang
,
M.
,
Li
,
Y.
,
Hu
,
Y. M.
,
Zhu
,
M. Y.
,
Jin
,
H. M.
, and
Li
,
W. X.
,
2015
, “
Nano-sized LiFePO4/C Composite With Core-Shell Structure as Cathode Material for Lithium Ion Battery
,”
Electrochim. Acta
,
176
, pp.
689
693
. 10.1016/j.electacta.2015.07.064
17.
Liang
,
N.
,
Zheng
,
L. G.
,
Qin
,
C. C.
,
Lu
,
Y. W.
,
Liu
,
P. X.
,
Wu
,
T. F.
,
Tang
,
Y. F.
, and
Chen
,
Y. F.
,
2014
, “
Fabrication and Characteristics of Spherical Hierarchical LiFePO4/C Cathode Material by a Facile Method
,”
Electrochim. Acta
,
147
, pp.
330
336
. 10.1016/j.electacta.2014.09.028
18.
Guan
,
X. M.
,
Li
,
G. J.
,
Li
,
C. Y.
, and
Ren
,
R. M.
,
2017
, “
Synthesis of Porous Nano/Micro Structured LiFePO4/C Cathode Materials for Lithium-Ion Batteries by Spray-Drying Method
,”
Trans. Nonferrous Met. Soc. China
,
27
, pp.
141
147
. 10.1016/S1003-6326(17)60016-5
19.
Xiao
,
Z. W.
,
Hu
,
G. R.
,
Du
,
K.
, and
Peng
,
Z.
,
2014
, “
A Facial Route Synthesis of LiFePO4/C Cathode Material With Nano-Sized Primary Particles
,”
Chin. J. Chem. Eng.
,
22
(
5
), pp.
590
595
. 10.1016/S1004-9541(14)60067-7
20.
Huang
,
B.
,
Zheng
,
X. D.
,
Jia
,
D. M.
, and
Lu
,
M.
,
2010
, “
Design and Synthesis of High-Rate Micron-Sized, Spherical LiFePO4/C Composites Containing Clusters of Nano/Microspheres
,”
Electrochim. Acta
,
55
(
3
), pp.
1227
1231
. 10.1016/j.electacta.2009.10.018
21.
Liu
,
H. B.
,
Miao
,
C.
,
Meng
,
Y.
,
He
,
Y. B.
,
X
,
Q.
,
Zhang
,
X. H.
, and
Tang
,
Z. Y.
,
2014
, “
Optimized Synthesis of Nano-Sized LiFePO4/C Particles With Excellent Rate Capability for Lithium Ion Batteries
,”
Electrochim. Acta
,
130
, pp.
322
328
. 10.1016/j.electacta.2014.03.034
22.
Xia
,
S. B.
,
Li
,
F. S.
,
Chen
,
F. X.
, and
Guo
,
H.
,
2018
, “
Preparation of FePO4 by Liquid-Phase Method and Modification on the Surface of LiNi0.80Co0.15Al0.05O2 Cathode Material
,”
J. Alloys Compd.
,
731
, pp.
428
436
. 10.1016/j.jallcom.2017.10.047
23.
Song
,
H. J.
,
Sun
,
Y. L.
, and
Jia
,
X. H.
,
2015
, “
Hydrothermal Synthesis of Iron Phosphate Microspheres Constructed by Mesoporous Polyhedral Nanocrystals
,”
Mater. Charact.
,
107
, pp.
182
188
. 10.1016/j.matchar.2015.07.013
24.
Lu
,
Y. J.
,
Huang
,
Y. D.
,
Zhang
,
Y.
,
Cai
,
Y. J.
,
Wang
,
X. C.
,
Guo
,
Y.
,
Jia
,
D. Z.
, and
Tang
,
X. C.
,
2019
, “
Synthesis of Sulfur/FePO4/Graphene Oxide Nanocomposites for Lithium–Sulfur Batteries
,”
Ceram. Int.
,
42
(
9
), pp.
11482
11485
. 10.1016/j.ceramint.2016.04.017
25.
Sawas
,
A.
,
Babu
,
G.
,
Thangavel
,
N. K.
, and
Arava
,
L. M. R.
,
2019
, “
Electrocatalysis Driven High Energy Density Li-Ion Polysulfide Battery
,”
Electrochim. Acta
,
307
, pp.
253
259
. 10.1016/j.electacta.2019.03.191
26.
Jin
,
Y. J.
,
Liu
,
F.
,
Tong
,
M. P.
, and
Hou
,
Y. L.
,
2012
, “
Removal of Arsenate by Cetyltrimethylammonium Bromide Modified Magnetic Nanoparticles
,”
J. Hazard. Mater.
,
227–228
, pp.
461
468
. 10.1016/j.jhazmat.2012.05.004
27.
Vigderman
,
L.
,
Khanal
,
B. P.
, and
Zubarev
,
E. R.
,
2012
, “
Functional Gold Nanorods: Synthesis, Self-Assembly, and Sensing Applications
,”
Adv. Mater.
,
24
(
36
), pp.
4811
4841
. 10.1002/adma.201201690
28.
Li
,
Y.
,
Wang
,
J.
,
Yao
,
J.
,
Du
,
Z. Q.
,
Gu
,
H.
, and
Wang
,
Z. T.
,
2019
, “
Enhanced Cathode Performance of LiFePO4/C Composite by Novel Reaction of Ethylene Glycol With Different Carboxylic Acids
,”
Mater. Chem. Phys.
,
224
, pp.
293
300
. 10.1016/j.matchemphys.2018.12.042
29.
Wei
,
Y.
,
Lei
,
H.
,
Huang
,
Z. L.
, and
Qi
,
T. G.
,
2017
, “
Preparation and Electrochemical Performances of Magnesium or Zircon Doped Lithium Iron Phosphates
,”
J. Wuhan Ins. Technol.
,
39
, pp.
450
454
.
30.
Zhang
,
L. Y.
,
Tang
,
Y. F.
,
Liu
,
Z. Q.
,
Huang
,
H. N.
,
Fang
,
Y. Z.
, and
Huang
,
F. Q.
,
2015
, “
Synthesis of Fe2P Coated LiFePO4 Nanorods With Enhanced Li-Storage Performance
,”
J. Alloys Compd.
,
627
, pp.
132
135
. 10.1016/j.jallcom.2014.12.046
31.
Xia
,
J.
,
Zhu
,
F. L.
,
Wang
,
G. R.
,
Wang
,
L.
,
Meng
,
Y. S.
, and
Zhang
,
Y.
,
2017
, “
Synthesis of LiFePO4/C Using Ionic Liquid as Carbon Source for Lithium Ion Batteries
,”
Solid State Ionics
,
308
, pp.
133
138
. 10.1016/j.ssi.2017.06.007
32.
Liu
,
Y. Y.
,
Liu
,
H.
,
An
,
L. W.
,
Zhao
,
X.
, and
Liang
,
G.
,
2019
, “
Blended Spherical Lithium Iron Phosphate Cathodes for High Energy Density Lithium-Ion Batteries
,”
Ionics
,
25
(
1
), pp.
61
69
. 10.1007/s11581-018-2566-7
33.
Gao
,
C.
,
Zhou
,
J.
,
Liu
,
G. Z.
, and
Wang
,
L.
,
2017
, “
Synthesis of F-Doped LiFePO4/C Cathode Materials for High Performance Lithium-Ion Batteries Using Co-precipitation Method With Hydrofluoric Acid Source
,”
J. Alloys Compd.
,
727
, pp.
501
503
. 10.1016/j.jallcom.2017.08.149
You do not currently have access to this content.