IONICS
·
2021
·Vol. 27
·期 11
·4673-4686
·
IF 2.817
Zhang Lei,Zhang Xuping,Wang Li,Zhuang Quanchao,Ju Zhicheng,Cui Yanhua
LiMn 0.8 Fe 0.2 PO 4 by coating with carbon and reducing the particle size to nanometric scale can be used as a superb cathode material for lithium-ion batteries. In this study, LiMn 0.8 Fe 0.2 PO 4 /C composite is synthesized by high-energy milling method, and the charge and discharge test results show that it has high capacity and good cycle stability. The electrochemical impedance spectra (EIS) of LiMn 0.8 Fe 0.2 PO 4 /C cathodes are obtained in the initial lithiation and delithiation process. It is found that the Nyquist plots of LiMn 0.8 Fe 0.2 PO 4 /C cathodes mainly consist of three parts in the lithiation and delithiation process, namely, high-frequency semicircle, middle-frequency semicircle, and low-frequency line. The above three parts are assigned to Schotty contact problem, charge transfer step, and lithium-ion solid-state diffusion process, respectively. A quantitative analysis of the variations of the resistance and barrier capacitance of Schotty contact with the polarization potential of the electrode and a reasonable explanation is given, as well as the resistance and space charge layer capacitance of charge transfer. Moreover, the change of n (a parameter in constant phase angle element (CPE) with a value between − 1 and 1) value is briefly discussed.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Yan Wang,Fubao Yong,Zhihua Wang,Miao Wang,Qian Peng,Min Zhao,Zhen Chen,Qi Huang,Shanshan Yang,Faquan Yu
In order to unlock the electrochemical performance ability of manganese-based lithium ferromanganese phosphate cathode materials, CP1–LiMn0.8Fe0.2PO4/C (coprecipitation) nanocomposites were prepared by introducing polystyrene nanospheres as templates and carbon sources into the coprecipitation method combined with a multistage carburizing heat treatment. In the processes of heat treatment, polystyrene nanospheres can not only build a conductive carbon layer and optimize the electron transport path but also refine the particles and inhibit the nanoparticle aggregation. The interconnected conductive carbon coating significantly improves the diffusion coefficient of lithium ions, which assists LiMn0.8Fe0.2PO4 in lifting discharge specific capacity and cycle performance. The test results show that the as-prepared CP1–LiMn0.8Fe0.2PO4/C shows superior rate capability (130.5 mAh g–1 at 0.1C and 92.8 mAh g–1 at 5C) and capacity reversibility (95.5% after 200 cycles at 0.5C).
研究领域:
材料科学
·
电化学
·
纳米技术
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
B.Z. Li,Y. Wang,L. Xue,X.P. Li,W.S. Li
A novel LiMn 0.8 Fe 0.2 PO 4 /C composite is synthesized via a sol–gel process. In this composite, acetylene black is embedded in LiMn 0.8 Fe 0.2 PO 4 . The structure and morphology of the resulting composite are characterized with XRD , SEM, TEM, and BET, and its performance as the cathode of lithium ion battery is investigated by charge–discharge test and EIS , with a comparison of the sample prepared without embedding acetylene black. It is found that the embedded composite exhibits better performance than the non-embedded sample. The former delivers a reversible capacity of 160 mAh g −1 , while the latter only 142 mAh g −1 at 0.1 C (1C = 150 mAh g −1 in the work). The embedded acetylene black not only functions as a barrier for the growing of LiMn 0.8 Fe 0.2 PO 4 particles in the preparation process, which is important for the formation of nano-particles, but also helps build a stable conductive network, thus improving the charge–discharge performance of LiMn 0.8 Fe 0.2 PO 4 .
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
电池技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Jiaqi Huang,Xinglin Tang,Yuqi Zhou,Ting Wang,Fangzhou Zhao,Weijian Wang,Yan Meng,Wanglai Cen,Yongzhi Zhang
The practical application of manganese-rich lithium manganese iron phosphate, i.e., LiMn0.8Fe0.2PO4, is limited by poor cycling stability and severe voltage decay. In this study, a novel and facile Zn-gradient doping strategy has been employed to enhance the structural stability and lithium-ion de-intercalation kinetics, thereby suppressing the voltage decay of LiMn0.8Fe0.2PO4/C (LMFP/C). Compared to the pristine LMFP/C, the Zn-gradient doped LiMn0.8Fe0.2PO4/C (Zn-LMFP/C) exhibits significantly enhanced cycling stability with the capacity retention increasing from 64.11% to 97.47% and suppressed voltage decay with the energy retention increasing from 60.75% to 96.06% after 300 cycles at 1C. Furthermore, the reversible capacity of Zn-LMFP/C is 157.21 mA h g−1 at 0.1C and 138.88 mA h g−1 at 5C, much higher than those of most of the Mn-rich LMFP/C materials reported in previous literature. Cyclic voltammetry (CV) and Galvanostatic Intermittent Titration Technique (GITT) results show that the delithiation/lithiation kinetics of Zn-LMFP/C are notably enhanced. Further first-principles calculations confirm that Zn-LMFP/C possesses superior structural stability and lithium-ion diffusion kinetics. These findings underscore the effectiveness of gradient doping in improving the electrochemical stability of LMFP, providing a promising strategy to mitigate voltage decay and enhance the long-term performance of high-capacity cathode materials for lithium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 40
·26070-26077
·
IF 4.036
Yuanchao Li,Baoyan Xing,Huishuang Zhang,Mengjie Wang,Li Yang,Guangri Xu,Shuting Yang
Iron (Fe) substitution is an effective strategy for improving the electrochemical performance of LiMnPO4 which has poor conductivity. Herein, we focus on investigating the effect of substitution of Mn with different iron sources, on the structure and electrochemical performances of the LiMnPO4 materials. The Fe-substituted LiMnPO4/C composites were synthesized via a simple and rational solid-state method, and will be of benefit for engineering applications. The characterization of the materials shows an obvious influence of the iron sources on structure and morphology. The N-LMFP material prepared using soluble FeNO3 as iron sources exhibits an excellent rate capacity of 122 mA h g−1 at 5C, and superior cyclability with a capacity retention of 98.9% after 400 cycles at 2C. The enhanced rate capability and cycling stability of N-LMFP are the result of the lowered electron/ion resistance and the improved reversibility of the reaction, that originates from the homogeneous fine particles and hierarchical structure with large mesopores. This research provides significant guidelines for designing an LiMnPO4 cathode with a high performance.
研究领域:
材料科学
·
电化学
·
储能技术
·
无机合成
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2022
·
IF 6.959
Yuanchao Li,Baoyan Xing,Zhenguang Wang,Huishuang Zhang,Yanyan Liu,Jianchun Jiang,Shuting Yang,Baojun Li
The construction of an ionic/electronic conducting network is crucial for achieving satisfactory electrochemical performances of LiMnPO4 materials because of their low conductivity and the dissolution of Mn2+. Herein, a hierarchical LiMn0.8Fe0.2PO4/C composite comodified with Li3PO4 and graphite is synthesized via a facile solid-state method combined with freeze drying. The ionic conductor Li3PO4 in situ generated can improve the lithium-ion conductivity and inhibit the reaction of Mn ions with electrolytes. An electronic conducting network is formed through the secondary coating graphite and the residual carbon in situ created within the grain boundaries of LiMnPO4 nanocrystallites. Taking advantage of the synergy effect, the Li3PO4 and graphite comodified LiMn0.8Fe0.2PO4/C material yields an initial discharge capacity of 150 mA h g–1at 0.1 C, a high-rate reversible capacity of 136 mA h g–1at 5 C, and a long-term capacity retention of 91.6% after 500 cycles at 2 C. The design strategy provides a significant inspiration for the development of high-performance cathode materials with practical application.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
固体化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）