INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2013
·
IF 2.596
Quancai Li,Chunxia Li,Cheng Yang,Chenchang Liu,Guangli Yu,Huashi Guan
Three derivatives of polymannuronic acid (PM) were prepared by chemically polyanionic modification. PM was substituted with phosphate ( OPO 3 2− ), H-phosphonate ( OPO 2 H − ) and sulfate ( OSO 3 − ) groups with the degree of substitution (DS) of 0.41, 1.42 and 1.04, respectively. The structures of all PM derivatives were characterized by FT-IR, 31 P NMR and 13 C NMR spectroscopy . The weight average molecular weight (Mw) was determined by high performance gel permeation chromatography (HPGPC). The antioxidant activities of PM and its derivatives were evaluated in vitro. The results indicated that both phosphate and H-phosphonate groups improved the hydroxyl radical scavenging activity, while sulfate group enhanced the superoxide radical scavenging activity. However, all of the derivatives scavenged DPPH less effectively than PM. The mechanism for how the different anionic substituent groups influenced the antioxidant activities was discussed.
研究领域:
生物化学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2024
·
IF 2.7
Caixia Huang,Lucheng Li,Peng Yang,Jun Chen
Although many researchers continue to pursue improved battery capacity, battery safety remains a major concern. The main cause of battery fires is the flammability of the currently available commercial organic liquid electrolytes, which are mainly composed of 1 M lithium hexafluorophosphate (LiPF6) and EC-containing carbonate solvents. Herein, a flame-retardant co-solvent tris(2,2,2-trifluoroethyl) phosphite (TTFP) was applied to improve the flame retardancy of a battery. It could improve the battery's discharging capacities at both 4.2 V and high cut-off voltage (4.5 V). Specifically, at a common voltage of 4.2 V, the cells’ 100th discharge capacity without TTFP was 130 mA h g−1 by 0.2C with a capacity retention (CR) of 69%. In comparison, under the same conditions, the capacity of the 10% TTFP-containing cell was 162.3 mA h g−1 with a CR of 73.9%. This increase in the electrochemical properties of the cell is clearly due to the addition of TTFP. When charging and discharging at 2.75–4.5 V, the capacity of the battery with STD after 100 cycles at 0.2C was 118.7 mA h g−1, and the corresponding CR was 60.93%. Meanwhile, the discharged capacity of the battery containing 10% TTFP was 150.0 mA h g−1 with a corresponding CR of 65.39%. Through combustion test with and without the TTFP electrolyte, it can be concluded that the TTFP-containing electrolyte is difficult to ignite. This result indicates that TTFP can efficiently enhance the safety performance of the battery. Thus, the incorporation of TTFP can be beneficial to improve the flame retardancy of the electrolyte. Moreover, TTFP does not affect the electrochemical stability of batteries. Thus, the present work may provide a good direction for the next generation of high-performance and high-safety lithium-ion batteries.
研究领域:
材料科学
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能源科学
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产品关联
DOI
高影响因子
RUSSIAN CHEMICAL BULLETIN
·
2024
·Vol. 73
·期 9
·2725-2729
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IF 1.7
Yang Zhihui,Wang Xiaochen,Wang Yuanrong,Yang Jinyun,Lu Haifeng
A new route for the synthesis of siloxanes containing substituents with the phosphonate and amino groups based on the catalyst-free Kabachnik—Fields reaction was developed. The synthesis was accomplished under mild conditions using 3-aminopropylsilanes, cyclic ketones, and diethyl phosphite as the starting materials to give the corresponding 1-(3-silylpropylamino)cycloalkylphosphonates in high yields.
研究领域:
有机化学
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药物化学
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材料化学
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分子合成
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功能材料
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DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Peng Zhang,Jian-Hua Cao,Wei-Hua Liang,Yue Li,Ya-Kun Wang,Da-Yong Wu
Solid electrolytes are generated through in situ polymerization within batteries, which is one of the most promising methods for achieving solid-state lithium metal batteries with good interfacial contact, high safety, and high performance. Poly-1,3-dioxolane (PDOL), although a good in situ solidified electrolyte for lithium stability, has poor applicability in high-voltage battery systems. In order to improve the interfacial compatibility between PDOL and both the cathode and anode of high-voltage batteries. we herein design a sacrificial additive, diethyl (2,2,2-trifluoroethyl) phosphite (DETFPi), with a lower lowest unoccupied molecular orbital (LUMO) and higher highest occupied molecular orbital (HOMO) energy, through methods of calculation. After being loaded into the battery, DETFPi-DOL is in situ polymerized to form DETFPi-PDOL electrolyte. The Li||DETFPi-PDOL||Li symmetric battery operates stably for 2000 h at 0.5 mA cm–2, with an overpotential of only 16 mV. XPS analysis shows that an SEI layer with high LiF content is formed on the surface of the lithium anode after cycling, which promotes the uniform deposition of lithium ions and inhibits the growth of lithium dendrites. After 300 cycles, the NCM811||DETFPi-PDOL||Li battery exhibits a remaining capacity of 154.8 mAh g–1 (81%) within the 3.0–4.35 V range, meanwhile demonstrating excellent rate performance. Moreover, a uniform CEI layer containing pentavalent phosphorus and low LiF content is formed on the surface of the cathode after battery cycling. Finally, due to the improvement of the cathode interface, the increase of interfacial impedance of the battery after 300 cycles is reduced to half that of the PDOL battery.
研究领域:
材料科学
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电化学
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电池技术
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产品关联
DOI
高影响因子
Energy Technology
·
2019
·Vol. 7
·期 4
·1800981
·
IF 3.163
Bangwei Deng,Hao Wang,Xiang Li,Yan Ding,Daming Sun,Jun Ma,Mianzhong Chen,Tao Chen,Feng Gao,Meizhen Qu,Gongchang Peng
Tris(trimethylsilyl)phosphite (TMSPi) has been reported to be an excellent electrolyte additive. However, scarce reports exist on the effect of the charge cutoff potential on the cyclic stability using high-performance LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM622)–mesocarbon microbead (MCMB) full cells. Herein, a high-loading and repeatable NCM622–MCMB coin-type full cell is successfully prepared, and the role of TMSPi on such a full cell at charge cutoff potentials of 4.25 and 4.45 V is studied. Theoretical calculations and detailed analyses reveal that it is oxidized in the first charging process due to its unsaturated P—O bonds, thus forming a stable P—O—F-rich cathode electrolyte interphase and preventing severe decomposition of the electrolyte over NCM622 during long-term cycling. In addition, the P—O and Si—O bonds of TMSPi both display HF-scavenging ability. Moreover, TMSPi may react directly with the LiPF 6 -based electrolyte to form some intermediate products that can be reduced on the MCMB electrode, thereby modifying the solid electrolyte interphase and improving the stability of MCMB during lithium intercalation.
研究领域:
电化学
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材料科学
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能源存储
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锂离子电池
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界面化学
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电极材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）