NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 31
·15016-15023
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IF 3.925
Yayue He,Youjia Zhang,Zhenxi Li,Peng-Fei Cao,Huabin Yang,Shilun Gao
As a promising anode material for next-generation high-energy density lithium-ion batteries (LIBs), one of the main technical issues for silicon (Si) electrodes is the low initial Coulombic efficiency (ICE). By a pre-lithiation process, preparation of lithium–silicon (Li–Si) alloy electrodes can efficiently improve the ICE, thus leading to excellent electrochemical performance. Herein, with solid wastes as precursors, we report a cost-efficient approach for the fabrication of Li3.25Si anode materials via simple magnesiothermic reduction and then mechanical alloy reaction methods, combining the advantages of low-cost and high ICE. The prepared Li3.25Si@acetylene black (Li3.25Si@A) electrode exhibits excellent electrochemical performance with a high reversible capacity of 1138.9 mA h g−1 over 90 cycles at a current density of 100 mA g−1 and its ICE is as high as 107.7%, which is superior to that of the commercial Li3.25Si@A electrode. With a simple and low-cost manufacturing process and high ICE, the fabrication process will be definitely meaningful in achieving low-cost and high-capacity anode materials with a prolonged cycle life.
研究领域:
材料科学
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电化学
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能源存储
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可持续材料
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电池技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 48
·期 6
·8579-8588
·
IF 4.527
Sunyi Shen,Shaolei Song,Jinming Wang,Rong Li,Xingchao Li,Qiang Zhen
Microstructure control and multiple compounding methods in the synthesis stage can enhance microwave absorption performance of microwave absorbents. In this work, we successfully synthesized binary TiB 2 –SiC (TsBC) powders with hexagonal sheet (TiB 2 ) and particle (SiC) interlocking structures by sol-gel carbothermal reduction method. We investigated the effect of raw material ratio and synthesis temperature on the synthesized powders and evaluated the microwave absorption properties of the synthesized TsBC powders. It was found that the TsBC absorber exhibited excellent microwave adsorption properties with the minimum Reflection Loss ( R L ) reached −21.8 dB at 17.4 GHz corresponding to the thickness of 4 mm. This excellent performance was attributed to the interfacial polarization between TiB 2 –SiC interfaces and the multiple reflections between the sheet-particle interlocking structures.
研究领域:
材料科学
·
功能材料
·
复合材料
·
电磁学
·
无机非金属材料
✓ 已验证
DOI
高影响因子
IONICS
·
2023
·Vol. 30
·期 2
·749-757
·
IF 2.8
Cong Jun,Luo Shao-hua,Li Peng-yu,Li Kun,Wang Ya-feng,Yan Sheng-xue,Li Peng-wei,Chen Huan-huan
To realize the high value–added utilization of acid-washed iron red, in this paper, acid-washed iron red is used as raw material. Aiming at the problem of low conductivity of iron-based lithium ion batteries (LIBs) LiFePO 4 /C materials, different metal ions are doped in the iron position, and the microstructure and electrochemical properties of the obtained material are systematically studied. Here, LiFePO 4 /C is synthesized through simple carbothermal reduction method using acid-washed iron red as the iron source. On this basis, La (1%, 2%, 3%) doping modification is carried out. Then doped modification is performed on this basis, preferably 2% La-doped LiFePO 4 /C materials. The XRD patterns show that the diffraction peaks of the samples prepared at all doping amounts can be perfectly matched with the standard card ( PDF # 40–1499), and there is no impurity peak, all of which are pure phases. According to the refined data, it is clear that minor amount of La has successfully replaced the position of Fe and incorporated into the lattice. Electrochemical tests show that LiFe 0.98 La 0.02 PO 4 /C has the highest charge and discharge capacity of 146.5/138.2 mAh·g −1 in the first cycle at 0.5C, and the reversible specific capacity of 136.5 mAh·g −1 remains after 50 cycles. Furthermore, the first-principles calculations more strongly confirm that La doping can significantly improve the defects of low electronic conductivity of LiFePO 4 .
研究领域:
材料科学
·
电化学
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能源存储
·
无机非金属材料
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固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Xiangyang Zhuang,Yao Zhang,Lingxiao He,Yunfeng Zhu,Quan Shi,Quan Wang,Guanzhou Song,Xiaoxiao Yan,Liquan Li
Overheating caused by exothermic effect of magnesiothermic reduction reaction is usually considered as a drawback in preparing porous silicon anode materials for Li-ion batteries. However, in the present work, thermal effect is available in facile preparation of macroporous Si by tabletting pretreatment . The released heat in magnesiothermic reaction is easily accumulated on the tablet with high density, leading to the collapse of the mesoporous structure of the precursor and formation of uniform macroporous silicon . Such macroporous silicon shows a higher initial Coulomb efficiency (86.5%) and enhanced cycling stability in comparison with mesoporous silicon prepared without tabletting treatment. XRD analysis indicates that the reaction temperature decreases to 430–435 °C (based on set temperature), much lower than that of the reaction without pretreatment. Since the structure of product has less dependency on precursor, a wide variety of precursors can be used to synthesize macroporous silicon, e.g. low cost biosilica. Being ascribed to low reaction temperature, heating rate insensitivity, less dependency on precursor, enhanced cycling performance and high initial Coulomb efficiency of the Si products, the modified magnesiothermic reduction method is promising for application in fabricating Si anode.
研究领域:
材料科学
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电化学
·
纳米科技
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能源存储
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无机合成
·
功能材料
·
电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）