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 Power Sources Advances
·
2020
·
IF 0
Qiuhong Wang,Walid A. Daoud
Flow battery is a promising energy storage technology for facilitating utilization of renewable resources. While new types of flow batteries have been explored toward high energy density, hampering the power density due to high electrolyte viscosity and sluggish reaction kinetics. Discovery of an aqueous electrolyte with multi-electron transfer reaction is thus favorable for both high energy and power densities due to its multiple charge stored at the same concentration. Both criteria are crucial to improve the flexibility of cell design and widen the application potential. Herein, bismuth is pioneered as negative electrolyte (negolyte) for hybrid flow battery owing to its three-electron reaction and the significantly increased solubility in methanesulfonic acid. In conjunction with cerium electrolyte, a volumetric energy density of 90 Wh L −1 is achieved and simultaneously a high power density of 295 mW cm −2 at 90% state-of-charge is demonstrated using low-cost carbon electrode. Furthermore, a high volumetric capacity of 120 Ah L −1 is reached via adopting graphite felt, which is 100% of the theoretical specific capacity of 1.5 M bismuth negolyte.
研究领域:
电化学储能
·
能源材料
·
功能材料
·
应用电化学
·
可再生能源存储
✓ 已验证
DOI
Small Methods
·
2024
·Vol. 8
·期 7
·2301233
·
IF 10.7
Xiaolin Ye,Ningxin Xiong,Shaopei Huang,Qixing Wu,Hongning Chen,Xuelong Zhou
Tin-based hybrid flow batteries have demonstrated dendrite-free morphology and superior performance in terms of cycle life and energy density. However, the quick accumulation of electrodeposits near the electrode/membrane interface blocks the ion transport pathway during the charging of the battery, resulting to a very limited areal capacity (especially at high current density) that significantly hinders its deployment in long-duration storage applications. Herein, a conductivity-activity dual-gradient design is disclosed by electrically passivating the carbon felt near the membrane/electrode interface and chemically activating the carbon felt near the electrode/current collector interface. In consequence, the tin metals are preferentially plated at the region near electrode/current collector, preventing the ion transport pathway from being easily blocked. The resultant gradient electrode demonstrated an unprecedentedly high areal capacity of 268 mAh cm −2 at a current density of as high as 80 mA cm −2 . Numerical modeling and experimental characterizations show that the dual-gradient electrode differs from conventional electrodes with regard to their reaction current density distribution and electrodeposit distribution during charging. This work demonstrates a new design strategy of 3D electrodes for hybrid flow batteries to induce a desirable distribution of electrodeposits and achieve a high areal capacity at commercially relevant current densities.
研究领域:
电化学储能
·
材料科学
·
能源化学
·
电池技术
·
功能材料
·
电化学工程
✓ 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
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）