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
NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 26
·12109-12116
·
IF 3.3
Ming-Hui Cao,Ren-Yan Li,Fen-Fen Huang,Xin-Yin Cai,Miao Cui,Shi-Ya Lin,Jing-Yang Tian,Yuan-Ping Jiang,Zulipiya Shadike,Zheng-wen Fu
P2-Na0.6Li0.11Fe0.27−xMn0.62YxO2 (x = 0, 0.5%, 1%, and 2%) cathode materials were successfully prepared using a traditional solid-state method with ball milling-assisted modification. The effect of Y-doping on the crystal structure, grain size, morphology and sodium storage performance of Na0.6Li0.11Fe0.27Mn0.62O2 was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), galvanostatic charge–discharge cycling tests, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results demonstrated that the ball-milling pre-treatment method could effectively reduce the grain size and mitigate the aggregation of Na0.6Li0.11Fe0.27Mn0.62O2. Additionally, reasonable Y-doping (x = 1%) significantly enhances the rate capability and cycling stability of Na0.6Li0.11Fe0.27Mn0.62O2via improving the Na+ diffusion kinetics and the reversibility of the oxygen redox reaction. These results indicate that Na0.6Li0.11Fe0.26Mn0.62Y0.01O2 is a promising candidate material for high-rate and long-life cathodes for Na-ion battery application.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机固体化学
·
电池技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 44
·24900-24905
·
IF 2.936
Yanjie Wang,Chun Fang,Ying Huang,Qing Liu,Ruirui Zhao,Xuli Ding,Yunhui Huang
Organic compounds have been utilized in rechargeable batteries as electrode materials on account of their designable structures and reversible redox properties. However, most of them suffer from problems with dissolution resulting in poor electrochemical performance. In this work, we adapt a sodium salt of tetracyanoquinodimethane (NaTCNQ) to work as a high redox potential cathode material in sodium ion batteries (SIBs). A porous carbon coated separator is demonstrated to be an adsorption layer and prevents the dissolved active material from migrating to the anode side. The NaTCNQ cell assembled with a carbon layer containing 5% activated carbon (AC) exhibits a higher initial capacity and greatly improved cycling stability. Using a conductive adsorption layer in organic redox batteries is a promising pathway to develop high performance organic electrode materials for SIBs.
研究领域:
电化学
·
能源材料
·
纳米材料
·
电池技术
·
功能材料
✓ 已验证
DOI
高影响因子
TETRAHEDRON
·
2014
·Vol. 70
·期 47
·9033-9040
·
IF 2.817
Tao Liu,Meng-Meng Liu,Xiao-Wen Zheng,Chong-Yang Du,Xiang-Yang Cui,Lu Wang,Ling-Li Han,Zhang-Yu Yu
The redox reactions of p -hydroquinone and pyrocatechol undergo a two-proton-two-electron process in aqueous solution. We calculated their redox potentials at the B3LYP/6-311+G(d,p) level, and verified the values by employing cyclic voltammetry experiments. Then we selected seven substituent groups (–F, –Cl, –OH, –COOH, –CN, –NH 2 , and –NO 2 groups) to systematically investigate the substituent effect , including the sort, position, and number of the substituent, on the redox potentials of p -hydroquinone and pyrocatechol. The calculated results show that –NH 2 and –OH groups can decrease the redox potentials, while –F, –Cl, –COOH, –CN, and –NO 2 groups increase the potential values of p -hydroquinone and pyrocatechol. The calculations can accurately predict the substituent effects on the redox potentials of pyrocatechol and p -hydroquinone. We would expect that the accurate calculation results for the model systems could be applied in the prediction of electrode potentials of other molecules.
研究领域:
物理有机化学
·
电化学
·
计算化学
·
分子设计
·
生物电化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 7
·期 11
·5991-6000
·
IF 9.931
Weiguang Wang,Hua Tian,Gequn Shu,Dongxing Huo,Fang Zhang,Xiuping Zhu
A bimetallic thermally regenerative ammonia-based battery (B-TRAB) using inexpensive materials efficiently converts low-grade thermal energy into electricity with high power density. Through thermal regeneration of the anolyte, the B-TRAB system realized high-voltage discharge (1.38 V) with redox couples [Cu(II)/Cu and Zn(NH3)42+/Zn] and low-voltage charge (0.72 V) with Zn(II)/Zn and Cu(NH3)42+/Cu. Adding 2 M NH3 to the anolyte of a Cu/Zn-TRAB produced a peak discharge power density of 525 W m−2-electrode (120 W m−2-membrane), and the voltage (or current) and peak power could be doubled by connecting two cells in series (or parallel). In successive regeneration cycles, a maximum power density of 115 W m−2-electrode (26 W m−2-membrane) and a net energy density of 714 W h m−3 were produced at a constant current density of 100 A m−2. The power density was enhanced to 515 W m−2-electrode (118 W m−2-membrane) and maintained in successive cycles by adding acid to the regenerated catholytes, with a net energy density of 299 W h m−3 (discharged at a constant load of 12 Ω and charged at a constant current density of 100 A m−2). A thermal-electricity conversion efficiency of 0.95% (10.7% relative to the Carnot efficiency) was achieved.
研究领域:
能源材料
·
电化学工程
·
热电转换技术
·
可持续能源
·
功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yinwei Fu,Xiaofeng Lei,Huiming Yin,Xizheng Liu
Flexible lithium–air batteries (LABs) with a redox mediator (RM) in the electrolyte demonstrate enhanced round-trip efficiency. However, their cycle performance is unsatisfactory due to severe corrosion of the Li metal anode. Herein, we propose a two step gelatinization strategy to fabricate a gradient RMs (including LiI, TMPD, and DMPZ) gel electrolyte, in which the bare electrolyte gelatinization on the Li surface and then the electrolyte contained RMs sequentially gelled on the formed gel. The RMs mainly distributed at the surface and anchored at the cathode side. By suppressing the shuttle of RMs in the electrolyte and alleviating the passivation of the Li anode, the mid-charging potentials can reach 3.44 and 4.08 V at the 15th cycle with and without the LiI mediator, respectively. The energy efficiency is 63% even at the 150th cycle, whereas the corresponding energy efficiency are only 47% and 51% for the LABs with liquid and normal gel electrolytes, respectively. Moreover, the cycle life of the battery containing the gradient gel electrolyte is three times longer than that with the liquid electrolyte. The gel electrolyte further offers the flexibility of the device, and the laminated cells thus fabricated can readily operate under harsh bending conditions.
研究领域:
电化学
·
能源材料
·
纳米材料
·
界面化学
·
储能技术
·
先进电池
·
功能高分子
·
柔性电子
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·Vol. 39
·期 28
·16123-16131
·
IF 2.93
Yufei Wang,Shuanjin Wang,Min Xiao,Shuqin Song,Dongmei Han,Michael A. Hickner,Yuezhong Meng
Novel sulfonated poly (fluorenyl ether ketone) with pendant quaternary ammonium groups (SPFEKA) was successfully synthesized by one-pot copolymerization of bis(4-fluoro-3-sulfophenyl)sulfone disodium salt, 4,4′-difluorobenzophenone, bisphenol fluorene and 2,2′-dimethylaminemethylene-9,9′-bis(4-hydroxyphenyl) fluorene (DABPF). The chemical structures were confirmed by FT-IR, and 1 H NMR. The thermal properties were fully investigated by TGA . The synthesized copolymers SPFEKAs are soluble in aprotic solvents, and can be cast into membranes on a glass plate from their N,N′-dimethylacetamide (DMAc) solution. A new kind of amphoteric ion exchange membrane (AIEM) was obtained by immersed SPFEKA into 1 M sulfuric acid. The proton conductivities of these membranes are comparable to the most reported sulfonated polymers under the same conditions. The permeability of vanadium ions in vanadium redox flow battery (VRB) was effectively suppressed by introducing quaternary ammonium groups for Donnan exclusion effect . AIEM-20% possess a only 4.4% vanadium ion permeability of Nafion 115. Cell performance tests showed that the VRB assembled with AIEM-20% shows the highest coulombic efficiency (CE) at the current density of 50 mA/cm 2 , because of its lowest VO 2+ permeability. In conclusion, these ionomers could be promising candidates for ion-exchange membranes for VRB applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
膜科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Xin Guan,Huijie Pei,Xiaoyu Chen,Chen Chang,Siyuan Shao,Yu-Mo Zhang,Xingping Zhou,Hui Nie,Xiaolin Xie
The adsorption-catalysis synergy for accelerated conversion of polysulfides is critical toward the electrochemical stability of lithium-sulfur battery (LSB). Herein, a non-metallic polymer network with anion receptor units, trifluoromethanesulfonyl (CF 3 SO 2 -) substituted aza-ether, was in-situ integrated on PE separator, working as an efficient host for anchoring lithium thiophosphates (LPS) as redox mediators and polysulfides through Lewis acid-base interaction. The anchored LPS on the modified PE separator displayed a robust chemical adsorption ability towards polysulfides through the formation of S S bond. Meanwhile, LPS decreased the energy barrier of Li 2 S nucleation and promoted redox reaction kinetics. The battery with LPS decorated separator revealed a long cycling lifespan with a per cycle decay of 0.056 % after 600 cycles, and a competitive initial capacity of 889.1 mAh/g when the of sulfur cathode increased to 3 mg cm −2 . This work developed a new design strategy to promote the utilization of lithium phosphorus sulfide compounds in LSB.
研究领域:
电化学
·
能源材料
·
纳米材料
·
界面化学
·
储能技术
✓ 已验证
DOI
高影响因子
POLYMER
·
2011
·Vol. 52
·期 23
·5312-5319
·
IF 3.829
Dongyang Chen,Shuanjin Wang,Min Xiao,Dongmei Han,Yuezhong Meng
High-molecular-weight bulky-block poly(fluorenyl ether thioether ketone)s were successfully synthesized by a two steps one-pot protocol using N,N′ -dimethy- S -carbamate masked dithiols for vanadium redox flow battery (VRB) application. The followed sulfonation procedure gave birth to novel sulfonated block poly(fluorenyl ether thioether ketone)s (SPFETKs) with controlled ionic exchange capacities (IEC). Membranes with proton conductivities higher than (IEC > 1.66 mequiv. g −1 ) or comparable to (IEC < 1.66 mequiv. g −1 ) that of Nafion117 membrane were achieved. The VO 2+ permeabilities of SPFETKs membranes were much lower than that of Nafion117 membrane. The thermal properties, mechanical properties, oxidative stability , water uptake, proton conductivity, VO 2+ permeability and cell performance were investigated in detail.
研究领域:
高分子化学
·
能源材料
·
电化学
·
膜科学与技术
·
功能高分子
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）