JOM
·
2024
·Vol. 76
·期 8
·4169-4178
·
IF 2.1
He Jie,Liu Jiaming,Yu Xiuyuan,Yang Chao,Liu Qingsheng
LiFePO 4 has become a mainstream cathode material, owing to its good safety and low price. However, its intrinsic limitations in terms of electronic and ionic conductivities hinder its further advancements. To overcome this challenge, element doping has been explored to enhance its conductivity. Here, Na and F co-doped LiFePO 4 /C was successfully synthesized via a carbothermic method. Structural characterization techniques were employed to confirm the formation of Li 0.97 Na 0.03 FePO 3.97 F 0.03 with controllable particle sizes. The incorporation of Na and F ions into the LiFePO 4 lattice results in a reduction of the Li-O bond energy. This decrease in bond energy facilitates the extraction and insertion of lithium ions during the charge and discharge processes, subsequently improving the overall kinetics of lithium-ion diffusion. Simultaneously, lattice distortion induced by doping led to charge compensation and accelerated Li + migration. Benefiting from the enhancement of intrinsic conductivity and Li + diffusivity, the specific capacitance of the co-doped LiFePO 4 /C cathode material was found to be 160 and 110 mAh g −1 at 0.1 and 5 C, respectively. Further, density functional theory calculations showed that Na/F co-doping enhanced the structural evolution in the material and increased free carrier concentration in LiFePO 4 . This work demonstrates that synergistic Na and F co-doping can optimize the rate performance of LiFePO 4 by enhancing intrinsic conductivity and Li + diffusivity, suggesting promising applications of the co-doped LiFePO 4 /C in high-power lithium-ion batteries for electric vehicles and grid-level energy storage systems.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Longde Jiang,Jingde Luan,Yu Zhang,Qingyu Chi,Wengang Liu,Zheng Yan,Shaobai Li,Chen Zhao
Phosphorus-oxygen co-doped graphite carbon nitride (POx-CN) are successfully fabricated by in situ impregnation and two-stage thermal polycondensation to investigate the effect of Na + and Cl - on the photocatalytic hydrogen evolution from artificial seawater splitting. The as-prepared POx-CN exhibits a hydrogen evolution rate of 1054.29 μmolg −1 h −1 in artificial seawater , lower than fresh water , indicating that Na + and Cl - play an inhibitory effect on hydrogen evolution reaction . The theoretical calculation indicates that the phosphorus-oxygen binary doping changed the electrostatic potential of the modified layer in carbon nitride molecule, accelerating the electron transfer rate from the structural O in triazine ring to P-N bond. In artificial seawater, the competition between Na + and Pt 2+ at active sites in the modified layer and electron capture by Cl - in the mutual conversion of Cl - and chlorine radicals result in the reduction of hydrogen evolution efficiency.
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Yu Guo,Rongbo Guo,Xiaoshuang Shi,Shujuan Lian,Qiannan Zhou,Ying Chen,Weifeng Liu,Wei Li
In this study, cellulose-based superabsorbent hydrogel was synthesized from sodium carboxymethyl cellulose (CMC-Na), acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to enhance its water absorbency and salt tolerance for soil-conditioning applications in areas suffering from drought and soil salinization. Superabsorbent hydrogels (SHs) were prepared by CMC-Na and AMPS successfully, using chemical graft technology. Structure, morphology, thermal stability , and water absorbency of SHs were deduced. The cellulose-based hydrogel showed a high salt tolerance that the maximum water absorbency reached 604 and 119% in distilled water and saline water, respectively. The swelling behavior in aqueous solvents indicated that the water absorption of hydrogels was improved with the increasing ratio of CMC-Na. All SHs exhibited adsorption of nitrogen with the maximum adsorption of ammonia nitrogen 30 mg·g −1 and the presence of hydrogels could slow down the loss of nutrients in the soil. This study provided a feasible strategy that AMPS was substituted by CMC-Na to synthesize SHs with strong water absorbency and high salt tolerance which could be efficiently applied in agriculture as a soil conditioner.
研究领域:
材料科学
·
环境科学
·
农业科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Ce Li,Xu Zhang,V.C. Onah,Weiling Yang,Zhuang Leng,Xiliang Jiang,Fangming Zhang,Shasha Li,Yong Zhang,Yu Han,Huisheng Liu,Chun Li,Dingfu Zhou,Fanming Zeng
In analyzing the effect of alkali metal and alkaline earth metal oxide on the properties of tellurite glass , a series of tellurite glass samples doped with alkali metals and alkaline earth metals were prepared based on the TeO 2 -WO 3 -GdF 3 glass system by melt quenching method. Through tests and comprehensive analysis, the results show that after the F − ions successfully enter the glass network, the substitution of TeO 2 by alkali and alkaline earth metals could reduce the molar volume , which means the glass becomes more compacted. The influence on the glass network is mainly shown in [TeO 3 ] and [TeO 4 ] units. Alkali metals and alkaline earth metals could increase the asymmetry of the TWG: Eu 3+ glass network, shorten the critical distance, and increase luminescence intensity by 8.6 times and improve color purity to 94%. In addition, alkali metals could prolong the fluorescence lifetime , while alkaline earth metals could shorten it. Te 4+
研究领域:
材料科学
·
光学材料
·
玻璃物理
·
发光光谱学
·
无机化学
✓ 已验证
DOI
高影响因子
Advanced Materials Interfaces
·
2020
·Vol. 7
·期 19
·2000684
·
IF 4.948
Wenyan Chen,Donghui Xu,Yuancheng Chen,Tang Tang,Shaojie Kuang,Haikuo Fu,Wuyi Zhou,Xiaoyuan Yu
Using polyvinyl alcohol and N-rich polyacrylonitrile as carbon sources, uniform MFe 1– x Mn x PO 4 (M = Li, Na)/N-doped C nanofibers are synthesized by sol–gel pretreatment and an electrospinning method followed by calcination. The as-prepared nanofibers exhibit a 3D homogenous network with uniform distribution of MFe 1− x Mn x PO 4 nanoparticles. The lattice distorts after Mn-doping without altering the original crystalline structure, increasing conductivity and enhancing the efficiency of Li + /Na + diffusion. When applied for lithium ion batteries, the optimized LiFe 0.8 Mn 0.2 PO 4 /C nanofibers deliver a considerable initial capacity of 169.9 mAh g −1 with coulombic efficiency of 92.4%. It also displays the excellent cycling stability with reversible capacity of 160 mAh g −1 after 200 cycles at 0.1 C and high rate performances with the specific capacity of 93 mAh g −1 at 5 C. Furthermore, NaFe x Mn 1− x PO 4 /N-doped C nanofibers are also synthesized by the same method for sodium-ion batteries, which exhibit an initial capacity of 134 mAh g −1 and specific capacity of 106 mAh g −1 at 0.1 C and 90 mAh g −1 at 1 C after 200 cycles. Owing to the facile fabrication process, these nanofibers are promising cathodes for lithium/sodium ion batteries with excellent electrochemical performances.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
固态化学
✓ 已验证
DOI
高影响因子
Small
·
2021
·Vol. 17
·期 46
·2101887
·
IF 13.281
Jian Feng,Shao-hua Luo,Sheng-xue Yan,Yang Zhan,Qing Wang,Ya-hui Zhang,Xin Liu,Long-jiao Chang
Transition-metal selenides (TMSs) have emerged as prospective anode materials for sodium ion batteries (SIBs), owing to their considerable theoretical capacity and intrinsic high electronic conductivity. Whereas, TMSs still suffer from poor rate capability and inferior cycling stability induced by sluggish kinetics and severe volume changes during de/sodiation processes. Herein, a hierarchical composite consisting of a zinc-cobalt bimetallic selenide yolk and nitrogen-doped double carbon shell (denoted as Zn Co Se@NDC) is engineered and fabricated successfully. The architecture of the as-fabricated material improves the Na-ion storage performance via increasing the electron transfer kinetics, accommodating volume expansion, and mitigating the generation of by-products. As expected, the Zn Co Se@NDC electrode delivers superior sodium storage performance with long cycling stability (344.5 mAh g −1 at 5.0 A g −1 over 2000 long-term cycles) and high-rate performance (319.2 mAh g −1 at 10.0 A g −1 ). Meanwhile, the NVP@C//Zn Co Se@NDC full SIB cells are constructed successfully, retaining 96.3% of its initial capacity at 0.5A g −1 after 200 loops. The outstanding electrochemical performance and the construction of hybrid SIBs will have far-reaching influences on the development of the various rechargeable batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 47
·7497-7505
·
IF 5.342
Jiannan Cheng,Kai Tu,Enjie He,Jinying Wang,Lifen Zhang,Zhenping Cheng,Xiulin Zhu
A new photocontrolled iodine-mediated reversible-deactivation radical polymerization (RDRP) strategy to facilely prepare main-chain-type semifluorinated alternating block copolymers was successfully established under irradiation with blue LED light at room temperature, by using a semifluorinated alternating copolymer ((AB)n, where A represents α,ω-diiodoperfluoroalkane and B represents α,ω-unconjugated diene) as a macroinitiator and chain-transfer agent, and methacrylates, acrylates and styrene as the monomers. The end group of (AB)n terminated with perfluoroalkyl iodide –(CF2)n–I can be activated by Ru(bpy)3Cl2/AsAc-Na reducing quenching catalytic cycle which generates initial carbon centered radicals (–(CF2)n˙) to initiate the polymerization under blue LED light irradiation. The polymerization can reach a reversible equilibrium through effective oxygen–iodine halogen bonding in acetone and undergo a photocontrolled iodine-mediated RDRP process. In addition, the “living” features of this photocontrolled iodine-mediated RDRP system were confirmed by polymerization kinetics and controlled “on–off” light switching cycle regulation. What's more, different types of fluoropolymers can be introduced on the copolymer chains due to the powerful designability of (AB)n. Therefore, this strategy can provide a facile and highly efficient approach to the precision synthesis of main-chain-type semifluorinated alternating di/triblock polymers under visible light irradiation.
研究领域:
高分子化学
·
材料科学
·
光化学
·
有机化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 28
·15807-15819
·
IF 12.732
Wenxi Zhao,Xiaodeng Wang,Xiaoqing Ma,Luchao Yue,Qian Liu,Yonglan Luo,Yang Liu,Abdullah M. Asiri,Xuping Sun
Pseudocapacitive electrochemical Na+-storage has been highlighted as one of the exploitable strategies for overcoming the sluggish diffusion-limited redox kinetics due to the effective structural preservation and fast ion-adsorption/desorption at the surface or quasi-surface of electrode materials. However, exploiting pseudocapacitive hosts with a micro–nano hierarchitecture and further achieving competitive pseudocapacitive contributions are still in their infancy so far. Herein, a yolk–shell NiS2/CuS hollow microspherical architecture with superb kinetically pseudocapacitive features was successfully constructed through an in situ hydrothermal sulfidation and subsequent ion-exchange route using Ni-based bimetallic (NiZn) organic frameworks (NiZn-MOFs) as a template precursor. As expected, the strongly synergistic coupling effect and hollow structural characteristic of the NiS2/CuS heterostructure enabled fast charge transfer and Na+ immigration, as well as the release of the mechanical stress/strain induced by the conversion reaction, and not unexpectedly, the NiS2/CuS electrode afforded extraordinary Na+-storage capability, including a remarkable specific capacity of 410.9 mA h g−1 after 750 cycles at 2.0 A g−1, excellent rate capability, and prolonged cyclability in terms of a remarkable 283.4 mA h g−1 even after 4200 cycles at 20.0 A g−1. More significantly, the kinetic analysis demonstrated that the electrochemical charge storage of the NiS2/CuS electrode manifested considerable pseudocapacitive contributions at all rates (90.0% to 96.9%), distinctly outperforming the previously reported NiS2-/CuS-based anodes. Furthermore, the density functional theoretical calculations suggested a fast Na+-transport kinetics and enhanced antibonding state energy level and Na2S adsorption energy due to the electronic redistribution and lattice distortion in the NiS2/CuS heterointerfaces.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
POLYHEDRON
·
2022
·
IF 2.975
Yan-Ling Deng,Wei Li,Chun-Yang Pan
Two new metal hybrid borates , Na[Ni(py) 2 ] 2 ·[(C 4 H 2 O 6 ) 2 B]·H 2 O (py = pyridine) ( 1 ) and [Cu(H 2 O) 2 (1-EI) 4 ]·[B 5 O 6 (OH) 4 ] 2 ·H 2 O (1-EI = 1-ethylimidazole) ( 2 ), have been successfully synthesized. 1 features an interesting structure based on mixed borate-tartrate motifs. Two tartrate anions are condensed with one BO 4 to form the hybrid anionic group [(C 4 H 2 O 6 ) 2 B] 5− . The structure of 2 is composed of [B 5 O 6 (OH) 4 ] − clusters and [Cu(H 2 O) 2 (1-EI) 4 ] 2+ complexes, which exhibits hydrogen-bonded network formed by [B 5 O 6 (OH) 4 ] − clusters. These compounds are further confirmed by FTIR, PXRD and UV–vis. In addition, the catalyst prepared from 2 shows excellent electrocatalytic oxygen reduction reaction (ORR) activity.
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）