Calcium Doping Effects on the Electrochemical Properties of LiFePO4/C Cathode Materials for Lithium-Ion Batteries

2012 ◽  
Vol 560-561 ◽  
pp. 499-505 ◽  
Author(s):  
George Ting Kuo Fey ◽  
Cyun Jhe Yan ◽  
Yi Chuan Lin ◽  
Kai Pin Huang ◽  
Yung Da Cho ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Solid State Method ◽  
X Ray ◽  
Doping Effects ◽  
Li Ion ◽  
Calcium Doping

This Olivine LiFe1-xCaxPO4/C composites (x=0 - 0.014) were synthesized by a solid-state method using sebasic acid as a carbon source. The structure and electrochemical properties of the LiFe1-xCaxPO4/C compounds were studied. The X-ray diffractometer (XRD) results indicated that Ca2+ doping did not affect the structure of the samples, but the unit cell volume of doped sample are slightly increased. Electrochemical measurements showed that the LiFe0.99Ca0.01PO4/C composite delivered a discharge capacity of 149 mAh g-1 at a 0.2 C-rate between 4.0 and 2.8 V, probably due to the significant improvement of electronic conductivity and Li+ ion diffusion. Besides, the cell can sustain a 20 C-rate, and this rate capability is equivalent to charge or discharge in 3 min.

Enhancing the Li+ diffusion in Li3VO4by coupling withreduced graphene oxide for lithium-ion batteries

2021 ◽  
Vol 17 ◽  
Author(s):  
Mingxuan Guo ◽  
Haibo Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Ion Diffusion ◽  
X Ray ◽  
Host Materials

Background: Owing to the excellent theoretical specific capacity and safety intercalation potential, Li3VO4¬ (LVO) has been proposed as anadvanced anode material for lithium ions batteries (LIBs). However, the LVO suffers from low electronic conductivity that limits its commercialization. Objective: The reduced graphene oxide (rGO) is recommended to couple with micro-LVO particles aiming to enhance the conductivity of compositeelectrodes. Method: The LVO@rGO compositeis synthesized by a facile hydrothermal method. The morphology, crystallinity, valance state and electrochemical behavior of LVO@rGO are characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical workstation, respectively. Further, the LIBs’ performance is explored by making a coins-type half-cell LIBs battery via battery system. Results: The Li+ diffusion rate of the optimized LVO@rGO electrode is 7.67×10-23 cm2 s-1, which improves two orders of magnitudesof pure LVO electrode. As a result, the LVO@rGO anode delivers a reversible capacity of 190.1 mAh/g at 0.1 A/g after 100 cycles, which is even twice higher than that of pure LVO anode (90.6 mAh/g). Besides,it exhibitssuperior rate capability, i.e.a reversible capability of 285.0, 220.2, 158.7, 105.2 and 71.7 mAh/g at 0.05, 0.1, 0.2, 0.5 and 1.0 A/g, respectively. Conclusion: The high conductivity and flexible texture enable rGO an idea building block to enhance the Li ion diffusion of whole electrode. On the other hand, it is instrumental in alleviating the aggregation of host materials, leading to high specific surface and specific capacity.

Synthesis and Electrochemical Properties of Spherical LiFePO4/C Composite via Spray Drying

2015 ◽  
Vol 1120-1121 ◽  
pp. 554-558 ◽  
Author(s):  
Juan Mei Wang ◽  
Bing Ren ◽  
Ying Lin Yan ◽  
Qing Zhang ◽  
Yan Wang
Keyword(s):  
Diffusion Coefficient ◽  
Electrochemical Properties ◽  
Spray Drying ◽  
Electrochemical Impedance ◽  
Retention Rate ◽  
Lithium Ion ◽  
Constant Current ◽  
Ion Diffusion ◽  
Electrochemical Tests ◽  
Li Ion

In this work, spherical LiFePO4/C composite had been synthesized by co-precipitation and spray drying method. The structure, morphology and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), transmission electron microscope (TEM), constant current charge-discharge tests and electrochemical impedance spectroscopy (EIS) tests. The spherical LiFePO4/C particles consisted of a number of smaller grains. The results showed that the morphology of LiFePO4/C particles seriously affected the Li-ion diffusion coefficient and electrochemical properties of lithium ion batteries. Electrochemical tests revealed the spherical LiFePO4/C composite had excellent Li-ion diffusion coefficient which was calculated to be 1.065×10-11 cm2/s and discharge capacity of 149 (0.1 C), 139 (0.2 C), 133 (0.5 C), 129 (1 C) and 124 mAhg-1(2 C). After 50 cycles, the capacity retention rate was still 93.5%.

Electrochemical Performance of Mg-Doped Li2FeSiO4/C as Cathode Material for Lithium-Ion Batteries

2013 ◽  
Vol 310 ◽  
pp. 90-94 ◽  
Author(s):  
Xiao Bing Huang ◽  
Hong Hui Chen ◽  
Huang Rong Li ◽  
Qian Peng Yang ◽  
Shi Biao Zhou ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Rate Capability ◽  
Lithium Ion ◽  
Impedance Spectra ◽  
X Ray Diffraction ◽  
Electrochemical Impedance Spectra ◽  
Solid State Method ◽  
X Ray ◽  
Mg Doped ◽  
Discharge Test

Li2FeSiO4/C and Li1.97Mg0.03FeSiO4/C composites were successfully prepared by a solid-state method. Both samples were systematically investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), the charge-discharge test and electrochemical impedance spectra measurement, respectively. It was found that the Li1.97Mg0.03FeSiO4/C composite exhibited an excellent rate capability with a discharge capacity of 144mAh g-1 at 0.2C and 97mAh g-1 at 5C, and after 100 cycles at 1 C, 96% of its initial capacity was retained.

scholarly journals Effect of PVP Coating on LiMnBO3 Cathodes for Li-Ion Batteries

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5528
Author(s):  
Bolong Hong ◽  
Xiangming He ◽  
Huihua Yi ◽  
Chenglin Hu
Keyword(s):  
High Capacity ◽  
Lithium Ion ◽  
Particle Growth ◽  
Li Ion Batteries ◽  
Ion Diffusion ◽  
Solid State Method ◽  
Structure Morphology ◽  
Carbon Additives ◽  
Li Ion ◽  
Lithium Ion Diffusion

LiMnBO3 is a potential cathode for Li-ion batteries, but it suffers from a low electrochemical activity. To improve the electrochemical performance of LiMnBO3, the effect of polyvinyl pyrrolidone (PVP) as carbon additive was studied. Monoclinic LiMnBO3/C and LiMnBO3-MnO/C materials were obtained by a solid-state method at 500 °C. The structure, morphology and electrochemical behavior of these materials are characterized and compared. The results show that carbon additives and ball-milling dispersants affect the formation of impurities in the final products, but MnO is beneficial for the performance of LiMnBO3. The sample of LiMnBO3-MnO/C delivered a high capacity of 162.1 mAh g−1 because the synergistic effect of the MnO/C composite and the suppression of the PVP coating on particle growth facilitates charge transfer and lithium–ion diffusion.

Self-recovery in Li-metal hybrid lithium-ion batteries via WO3 reduction

Nanoscale ◽  
2018 ◽  
Vol 10 (34) ◽  
pp. 15956-15966 ◽  
Author(s):  
Rajesh Pathak ◽  
Ashim Gurung ◽  
Hytham Elbohy ◽  
Ke Chen ◽  
Khan Mamun Reza ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Volume Expansion ◽  
Anode Materials ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Li Ion Batteries ◽  
Transitional Metal ◽  
Transitional Metal Oxides ◽  
Li Ion

It has been a challenge to use transitional metal oxides as anode materials in Li-ion batteries due to their low electronic conductivity, poor rate capability and large volume expansion.

Effect of Na Doping or Substitution on the Structural and Electrochemical Properties of Cobalt-Free Li-Rich Mn-Based Cathode Materials

2020 ◽  
Vol 1001 ◽  
pp. 181-190
Author(s):  
Wei Wei Li ◽  
Lu Yao ◽  
Jiang Ju Si ◽  
Jie Yang ◽  
Wu Ke Lang ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Cathode Materials ◽  
Photoelectron Spectroscopy ◽  
Rate Capability ◽  
Test System ◽  
Discharge Process ◽  
Layer Spacing ◽  
X Ray ◽  
Na Doping ◽  
Li Ion

Cobalt-free Li-rich Mn-based cathode materials are considered to be the next generation of Li-ion batteries due to low cost, high discharge capacities and high safety feature. However, there are still several serious issues that need to be solved urgently, such as low initial coulombic efficiency, low rate capability, poor cycling performance and voltage fading. Na doping or substitution is introduced to improve the electrochemical performance of Li1.2Mn0.6Ni0.2O2 cathode material, which is synthesized by sol-gel method. The effect of Na doping or substitution on the morphological, structural and electrochemical properties was systematically studied and analyzed by scanning electron microscope (SEM), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cell test system and electrochemical workstation. These results illustrate that lattice layer spacing is enlarged by Na doping or substitution, which is beneficial for the diffusion of Li-ion, and the voltage fading is successfully suppressed. The best electrochemical properties were obtained when Na doping, which is attributed to the stronger structural stability and better reversibility of Li+ during the initial charge and discharge process.

SURFACE DECORATION OF COMMERCIAL GRAPHITE MICROSPHERES WITH SMALL Si/C MICROSPHERES AS IMPROVED ANODE MATERIALS FOR Li-ION BATTERIES

2013 ◽  
Vol 01 (04) ◽  
pp. 1340017
Author(s):  
ZAILEI ZHANG ◽  
YANHONG WANG ◽  
MEIJU ZHANG ◽  
QIANGQIANG TAN ◽  
FABING SU
Keyword(s):  
Electron Microscopy ◽  
Composite Materials ◽  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Anode Materials ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Li Ion Batteries ◽  
X Ray ◽  
Li Ion

We report a facile chemical vapor deposition (CVD) method to grow silicon/carbon ( Si / C ) microspheres on commercial graphite microsphere (GMs) surface to prepare Si / C / GMs composite anode materials for Li -ion batteries. The CVD synthesis is conducted at 900°C using methyltrichlorosilane ( CH 3 SiCl 3) as both the Si and C precursor, which is a cheap byproduct in organosilane industry. The samples are characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy and X-ray photoelectron spectroscopy. It is found that the obtained Si / C / GMs composites are composed of Si nanocrystals, amorphous carbon and GMs. The CVD time significantly influences the morphology and electrochemical performance of the Si / C / GMs composite materials. The Si / C / GMs composite materials prepared at CVD condition of 900°C for 4 h possess improved electrochemical properties, showing a discharge capacity of 821.4 mAh g−1 at a rate of 50 mA g−1, and a good cycling performance (i.e., a reversible capacity of 565.2 mAh g−1 is retained after 50 cycles). The enhanced electrochemical performance is attributed to the formation of Si / C microsphere network among GMs, which increases the electronic conductivity and is able to buffer the large volume changes of Si during lithium ion insertion/extraction.

scholarly journals Recent Progress of TiO2-Based Anodes for Li Ion Batteries

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Yu Liu ◽  
Yefeng Yang
Keyword(s):  
Energy Storage ◽  
Active Sites ◽  
Recent Progress ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Energy Storage And Conversion ◽  
Ion Diffusion ◽  
Lithium Storage ◽  
Storage Mechanism ◽  
Li Ion

TiO2-based materials have been widely studied in the field of photocatalysis, sensors, and solar cells. Besides that, TiO2-based materials are of great interest for energy storage and conversion devices, in particular rechargeable lithium ion batteries (LIBs). TiO2has significant advantage due to its low volume change (<4%) during Li ion insertion/desertions process, short paths for fast lithium ion diffusion, and large exposed surface offering more lithium insertion channels. However, the relatively low theoretical capacity and electrical conductivity of TiO2greatly hampered its practical application. Various strategies have been developed to solve these problems, such as designing different nanostructured TiO2to improve electronic conductivity, coating or combining TiO2with carbonaceous materials, incorporating metal oxides to enhance its capacity, and doping with cationic or anionic dopants to form more open channels and active sites for Li ion transport. This review is devoted to the recent progress in enhancing the LIBs performance of TiO2with various synthetic strategies and architectures control. Based on the lithium storage mechanism, we will also bring forward the existing challenges for future exploitation and development of TiO2-based anodes in energy storage, which would guide the development for rationally and efficiently designing more efficient TiO2-based LIBs anodes.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF LITHIUM TITANATE (LTO) NANOCOMPOSITES VIA SOLUTION GROWTH ROUTE FOR Li-ION BATTERIES

2017 ◽  
Vol 4 (3) ◽  
pp. 10-13
Author(s):  
Selvamurugan M ◽  
Dhilip Kumar R ◽  
Karthikeyan C ◽  
Karuppuchamy S
Keyword(s):  
Lithium Ion ◽  
Lithium Titanate ◽  
Solution Growth ◽  
Li Ion Batteries ◽  
Ion Diffusion ◽  
X Ray Diffraction ◽  
Lithium Storage ◽  
Promising Alternative ◽  
X Ray ◽  
Li Ion

The novel bimetal oxide composite of Li4Ti5O12 was successfully synthesized by solution growth technique. The structural and microstructural properties of synthesized powders were characterized by powder X-ray diffraction (XRD), fourrier transform infrared spectroscopy (FT-IR), Raman spectroscopy,scanning electron microscopy (SEM) and energy dispersive X-ray-spectroscopy (EDX). The electrochemical performance of the Li4Ti5O12 anode was investigated using galvanostatic charge-discharge techniques. The electrochemical property of the Lithium titanate anode was investigated. The good electrochemicalperformance is ascribed to the stable lithium storage host structure, decreased electrochemical resistance and enhanced lithium-ion diffusion coefficient. Therefore, Li4Ti5O12 may be a promising alternative anode material for Li-ion batteries.

Synthesis and high cycle performance of Li2ZnTi3O8/C anode material promoted by asphalt as a carbon precursor

RSC Advances ◽  
2016 ◽  
Vol 6 (55) ◽  
pp. 49298-49306 ◽  
Author(s):  
Yurong Ren ◽  
Peng Lu ◽  
Xiaobing Huang ◽  
Jianning Ding ◽  
Haiyan Wang
Keyword(s):  
Anode Material ◽  
Electronic Conductivity ◽  
Rate Capability ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Carbon Layer ◽  
Cycle Performance ◽  
Carbon Precursor ◽  
Ion Diffusion ◽  
Lithium Ion Diffusion

A carbon layer (ca. 3 nm) formed on the surface of Li2ZnTi3O8 nanoparticles (ca. 30 nm) which is favorable to improve the electronic conductivity and lithium ion diffusion, resulting in improved rate capability and cycling performance.

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