ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Lili Chai,Qunting Qu,Longfei Zhang,Ming Shen,Li Zhang,Honghe Zheng
Chitosan was applied as the electrode binder material for a spherical graphite anode in lithium-ion batteries. Compared to using poly (vinylidene fluoride) (PVDF) binder, the graphite anode using chitosan exhibited enhanced electrochemical performances in terms of the first Columbic efficiency, rate capability and cycling behavior. With similar specific capacity, the first Columbic efficiency of the chitosan-based anode is 95.4% compared to 89.3% of the PVDF-based anode. After 200 charge–discharge cycles at 0.5 C , the capacity retention of the chitosan-based electrode showed to be significantly higher than that of the PVDF-based electrode. Electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) measurements were carried out to investigate the formation and evolution of the solid electrolyte interphase (SEI) formed on the graphite electrodes. The results show that a thin, homogenous and stable SEI layer is formed on the graphite electrode surface with chitosan binder compared with that using the conventional PVDF binder
研究领域:
电化学
·
材料科学
·
能源存储
·
电池技术
·
纳米材料
·
界面化学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2017
·
IF 2.354
Leyu Zhan,Yao Zhang,Xiangyang Zhuang,Hui Fang,Yunfeng Zhu,Xinli Guo,Jian Chen,Zengmei Wang,Liquan Li
The x LiBH 4 -Li 3 N ( x = 1, 2, 4) composites were investigated on their lithium ionic conductivities . They maintained the original phase structures of orthorhombic LiBH 4 and hexagonal β-Li 3 N during ball milling according to the analyses by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Electrochemical impedance spectra (EIS) tests showed that LiBH 4 -Li 3 N composites lift the lithium ionic conductivities from that of bulk LiBH 4 by nearly 100 times at low temperature. LiBH 4 -Li 3 N offers 1.06 × 10 − 5 S cm − 1 of conductivity while bulk LiBH 4 possesses only 2.05 × 10 − 7 S cm − 1 at 323 K. Cyclic voltammetry (CV) tests indicated that the voltage window of composites could attain 3 V, which is much more stable than Li 3 N (< 1 V). No thermodynamic incident appears in DSC curves except for the orthorhombic-hexagonal transition endothermic peak of LiBH 4 in the x LiBH 4 -Li 3 N composites. It confirms the phases stabilities of the x LiBH 4 -Li 3 N ( x = 1, 2, 4) composites before and after CV tests. In-situ solid state Nuclear Magnetic Resonance (NMR) tests on LiBH 4 -Li 3 N illustrated that the high conductivity in low temperature should not come from high-temperature phase of LiBH 4 . Therefore, the enhancement of lithium ionic mobility of the composite might be attributed to both Li 3 N and the interfaces between small crystallites where transmission electron microscope (TEM) morphology showed the appearance of amorphous grain boundary.
研究领域:
材料科学
·
固态离子学
·
能源化学
·
电化学
·
纳米材料
·
固体电解质
·
锂离子电池
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 87
·70743-70748
·
IF 3.84
Zhiwei Liu,Ping Li,Fuqiang Zhai,Qi Wan,Alex A. Volinsky,Xuanhui Qu
Nanostructured tungsten carbide with high surface area and containing amorphous carbon is prepared by a low temperature combustion synthesis method. The nanostructured tungsten carbide is used as the catalyst in a gas diffusion electrode. The obtained WC with different carbon content was investigated by XRD, FESEM, TG-DTA, BET and XPS. When the molar ratio of C/W is 19/3, the WC particles with different carbon content are obtained after a carbonizing process between 900 and 1400 °C, and the content of free carbon in WC also increases gradually with temperature. The carbon content is tested by the high frequency combustion-infrared absorption method in a carbon sulfur analyzer. The electrochemical properties of the tungsten carbide for the oxygen reduction reaction are characterized by its polarization curves and electrochemical impedance. The results show that the presence of the appropriate amorphous carbon is beneficial for improving the conductivity and dispersibility of the tungsten carbide catalyst, and more active centers can be provided by the catalyst.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
表面科学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2015
·Vol. 7
·期 9
·4171-4178
·
IF 7.394
Tingting Li,Huanhuan Li,Zhennan Wu,Hongxia Hao,Jiale Liu,Tingting Huang,Haizhu Sun,Jingping Zhang,Hao Zhang,Zuoxing Guo
The excellent electrochemical performance of greigite (Fe3S4) coupled with its vast abundance and low toxicity make it a good prospect as an anode material for lithium ion batteries (LIBs). In this research, a simple and feasible approach for producing pure phase, small sized, shape-controllable, and stable Fe3S4 nanoplates (NPs) through hot injection of sulfur solution into Fe(III) solution was demonstrated. The growth of Fe3S4 NPs involves the primary formation of a pyrite (FeS2) nucleus and subsequent Fe(III) doping. The lateral size of the Fe3S4 NPs was controlled further by tuning the experimental variable-dependent reactivity of Fe sources in the nucleation and growth stage. The Fe3S4 NPs embedded in LIBs present a low electrochemical resistance and are highly active in lithiation/delithiation processes.
研究领域:
材料科学
·
纳米科技
·
电化学
·
能源存储
·
无机化学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2018
·
IF 2.751
Xue Bai,Wen Li,Aijia Wei,Qian Chang,Lihui Zhang,Zhenfa Liu
Spinel Li 4 Ti 5 O 12 doped with F was synthesized via the solid-state reaction of anatase TiO 2 , Li 2 CO 3 , and NH 4 F. The structural characterization and electrochemical performance evaluation of the prepared materials were carried out utilizing X-ray diffraction, scanning electron microscopy, galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) tests. The lattice parameters of all samples were calculated using an internal standard and Rietveld refinement method. The results indicate that the F was successfully doped into the lattice structure of Li 4 Ti 5 O 12 , and this process did not influence the crystal structure and superficial morphology. Moreover, the best-performing material, Li 4 Ti 5 O 11.9 F 0.1 delivers superior rate capacities of 165, 162.1, 160.0, 142.3, 125.1, and 99.2 mAh g −1 , at 0.2 C, 0.5 C, 1 C, 3 C, 5 C, and 10 C, respectively, which is higher than those of Li 4 Ti 5 O 12 (150.0, 135.0, 123.5, 93.7, 76.4, and 56.8 mAh g −1 at the same C-rates), and the cycling retention is 82.7% after 150 cycles at 5 C. Meanwhile, the charge-transfer resistance (R ct ) of Li 4 Ti 5 O 11.9 F 0.1 (56.4 Ω) is lower than that of pure Li 4 Ti 5 O 12 (80.6 Ω), and the lithium-ion diffusion coefficients (D Li + ) of Li 4 Ti 5 O 11.9 F 0.1 (2.505 × 10 −10 cm 2 s −1 ) is higher than that of pure Li 4 Ti 5 O 12 (1.694 × 10 −10 cm 2 s −1 ).
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固体化学
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2018
·
IF 3.23
Hongjing Wu,Shaohua Qu,Kejun Lin,Yuchang Qing,Liuding Wang,Yuancheng Fan,Quanhong Fu,Fuli Zhang
It has been rarely reported that the microwave absorption materials can exhibit excellent low-frequency EM wave absorbing properties. In this paper, we synthesized steady short carbon fibers (SCFs)@TiO 2 composites by using simple one-pot hydrothermal process. The conductive short carbon fibers could be separated by TiO 2 nanoparticles from each other and reduced the conductivity of composite materials as a whole, meeting the requirements of impedance matching . With the introduction of SCFs content, SCFs@TiO 2 composites showed improved tan δ E values at low frequencies, implying the enhanced microwave attenuation ability at low and medium frequency. We unexpectedly found that the SCFs@TiO 2 composites exhibited very strong absorbing peaks ( i.e. , −46.3 dB) at low frequencies with relatively thin matching thickness. Interestingly, when the thickness of the SCFs@TiO 2 composite was only 1.0 mm, the absorbing bandwidth with a RL value less than −10 dB was over 14.3–16.7 GHz ( i.e. , absorbing frequency bandwidth is 2.4 GHz).
研究领域:
材料科学
·
电磁功能材料
·
纳米复合材料
·
微波吸收材料
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Naseem Akhtar,Hongyuan Shao,Fei Ai,Yuepeng Guan,Qifan Peng,Hao Zhang,Weikun Wang,Anbang Wang,Bingyin Jiang,Yaqin Huang
Lithium-sulfur (Li-S) batteries with high specific capacity are expected to be a new generation of energy storage devices. However, the shuttle effect of lithium polysulfide makes it difficult to commercialize stable Li-S batteries. In this work, we designed a gelatin-polyethylenimine composite (GPC) as functional binder for Li-S batteries to improve the stability of electrode during discharge-charge process. GPC binder combines the dispersion and adhesion ability of gelatin, which keeps cathode homogeneous and stable during electrochemical reaction , and adsorption capability of PEI for polysulfide , which suppresses the “shuttling effect”. The result shows that GPC used as a binder remarkably enhanced cyclic performance of Li-S battery with good capacity retention of about 100% at current density of 1C (sulfur loading 1.5 mg cm −2 ) after 100 cycles. We believe that GPC would be a promising binder for highly stable Li-S batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
纳米复合材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2017
·
IF 6.395
H.R. Jiang,W. Shyy,M.C. Wu,L. Wei,T.S. Zhao
The potential of B 4 C as a metal-free catalyst for vanadium redox reactions is investigated by first-principles calculations. Results show that the central carbon atom of B 4 C can act as a highly active reaction site for redox reactions , due primarily to the abundant unpaired electrons around it. The catalytic effect is then verified experimentally by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests, both of which demonstrate that B 4 C nanoparticles can enhance the kinetics for both V 2+ /V 3+ and VO 2+ /VO 2 + redox reactions, indicating a bi-functional effect. The B 4 C-nanoparticle-modified graphite felt electrodes are finally prepared and tested in vanadium redox flow batteries (VRFBs). It is shown that the batteries with the prepared electrodes exhibit energy efficiencies of 88.9% and 80.0% at the current densities of 80 and 160 mA cm −2 , which are 16.6% and 18.8% higher than those with the original graphite felt electrodes. With a further increase in current densities to 240 and 320 mA cm −2 , the batteries can still maintain energy efficiencies of 72.0% and 63.8%, respectively. All these results show that the B 4 C-nanoparticle-modified graphite felt electrode outperforms existing metal-free catalyst modified electrodes , and thus can be promising electrodes for VRFBs.
研究领域:
电化学
·
能源材料
·
催化化学
·
储能技术
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2016
·Vol. 26
·期 3
·481-487
·
IF 2.322
Zhen Zhang,Pengfei Zhou,Huanju Meng,Chengcheng Chen,Fangyi Cheng,Zhanliang Tao,Jun Chen
LiNi 0.915 Co 0.075 Al 0.01 O 2 (NCA) with Zr(OH) 4 coating is demonstrated as high performance cathode material for lithium ion batteries (LIBs). The coated materials are synthesized via a simple dry coating method of NCA with Zr(OH) 4 powders, and then characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Experimental results show that amorphous Zr(OH) 4 powders have been successfully coated on the surface of spherical NCA particles, exhibiting improved electrochemical performance . 0.50 wt% Zr(OH) 4 coated NCA delivers a capacity of 197.6 mAh/g at the first cycle and 154.3 mAh/g after 100 cycles with a capacity retention of 78.1% at 1 C rate. In comparison, the pure NCA shows a capacity of 194.6 mAh/g at the first cycle and 142.5 mAh/g after 100 cycles with a capacity retention of 73.2% at 1 C rate. Electrochemical impedance spectroscopy (EIS) results show that the coated material exhibits a lower resistance, indicating that the coating layer can efficiently suppress transition metals dissolution and decrease the side reactions at the surface between the electrode and electrolyte. Therefore, surface coating with amorphous Zr(OH) 4 is a simple and useful method to enhance the electrochemical performance of NCA-based materials for the cathode of LIBs.
研究领域:
电化学
·
材料科学
·
能源存储
·
电池技术
·
无机非金属材料
·
固态化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·Vol. 50
·期 14
·24995-25004
·
IF 5.1
Zhiyi Li,Haili Sun,Wei Wei,Fengxia Liu,Xiaofei Xu,Zhijun Liu
The emerging market of high-power lithium-ion batteries (LIBs) highlights the importance of developing high-voltage cathodes. Lithium nickel phosphate (LiNiPO 4 ) with the highest theoretical discharge potential (∼5.1V) has attracted increasing attention due to its stable olivine structure. In this study, ultrathin carbon layer-coated LiNiPO 4 was synthesized using oleylamine-assisted solvothermal method under different solvothermal times, and the effect of solvothermal time (1h–18h) on LiNiPO 4 samples is fully investigated. X-ray diffraction (XRD) shows that high-purity LiNiPO 4 materials can be prepared after calcination of the solvothermal product under N 2 , but adding part of H 2 to the calcination atmosphere will lead to the generation of impurities in the target product. As the solvothermal time increases, the product will agglomerate and grow, the particle size will increase, and the morphology will change from nanoparticle to rodlike structure. After the high-temperature calcination step, the oleylamine is completely carbonized, and a conductive carbon layer is successfully coated on the LiNiPO 4 with the thickness of 2 nm. As the solvothermal time increases, the graphitization degree of oleylamine increases after carbonization. The existence of the carbon layer and the increase in the degree of graphitization are beneficial to improving the electrical conductivity and Li-ion diffusion rate of LiNiPO 4 . The initial discharge capacity of LNP@C-12h product prepared with 12 h solvothermal time is 35 mA h g −1 at 0.1 C. Rietveld analysis shows that the anti-site defect concentration of the LNP@C material is 1.07 %, and the proportion increases to 2.83 % after several cycles. This work provides a positive contribution to the synthesis and modification of high-voltage LiNiPO 4 materials and explains the electrochemical performance degradation of LiNiPO 4 from the perspective of increasing the concentration of anti-site defects.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
锂离子电池
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2016
·Vol. 42
·期 7
·3947-3954
·
IF 3.205
Jialei Jin,Yuanzhi Zhu,Yizhe Liu,Yang Li,Wenchao Peng,Guoliang Zhang,Fengbao Zhang,Xiaobin Fan
Producing hydrogen through hydrogen evolution reaction by electrolyzing water is a great alternative to solve the energy crisis and air pollution. Earth abundant transition-metal phosphides, especially CoP , have emerged as promising hydrogen evolution reaction catalysts for recent years. Nowadays, attention is focused on combining CoP with other materials to improve its catalytic activity . Herein, in order to get better hydrogen evolution reaction catalyst, we combined CoP nanoparticles with WS 2 nanosheets. Different CoP to WS 2 mass ratios were set to find the best catalytic activity. CoP/WS 2 composites were prepared through a simple ultrasound induced mixing method. And all the CoP/WS 2 composites have enhanced hydrogen evolution reaction catalytic activity than pure CoP nanoparticles and WS 2 nanosheets. Especially, the optimized CoP/WS 2 composite has the lowest onset overpotential of 50 mV, the largest current density of 78 mA/cm 2 at the overpotential of 300 mV, and the smallest Tafel slope of 64.63 mV/decade, indicating excellent hydrogen evolution reaction catalytic activity.
研究领域:
材料科学
·
电化学
·
纳米催化
·
能源材料
·
无机功能材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2012
·Vol. 39
·期 5
·5379-5385
·
IF 1.751
Jingjing Zhou,Jiefeng Zhou,Yuanhao Tang,Yujing Bi,Chenyun Wang,Deyu Wang,Siqi Shi
Using NaF as the only Na precursor, fluorophosphate Na 2 FePO 4 F/C materials have been synthesized via the solid-state reaction. Na 2 FePO 4 F starts to form at 300 °C, becomes the sole crystalline form between 400 and 600 °C, and decomposes at 650 °C. Comparing with the theoretical capacity of 124 mAh g −1 , the sample prepared at 600 °C delivered a discharge capacity of 118 mAh g −1 . The outstanding electrochemical performance is believed to result from the good crystallization and high purity of the synthesized materials . The capacity retentions at 0.5 C and 2 C are 95.8% and 89.8%, respectively, of that at 0.05 C. Furthermore, a discharge capacity of 122 mAh g −1 is maintained under the cycling between 2.0 and 5.2 V vs. Li/Li + , indicating that the second Na + is not extracted from the Na 2 FePO 4 F lattice.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机化学
·
固体化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）