RSC Advances
·
2016
·Vol. 6
·期 32
·27164-27169
·
IF 3.289
Han Xu,Jun Zong,Fei Ding,Zhi-wei Lu,Wei Li,Xing-jiang Liu
To improve the electrochemical performance of LiMnPO4, a modified polyol reaction has been successfully developed for the preparation of LiMnxFe1−xPO4/C samples (x = 0.2, 0.5, 0.8). The secondary particles of the acquired LiMnxFe1−xPO4/C samples are spherical or annular, and the primary particles are nano-sized (20–80 nm). The LiMn0.8Fe0.2PO4/C has a higher energy density of 637 W h kg−1 compared with LiMn0.2Fe0.8PO4/C (575 W h kg−1) and LiMn0.5Fe0.5PO4/C (584 W h kg−1). The TEM image shows that the primary particles of LiMn0.8Fe0.2PO4/C are uniformly covered by a 3 nm carbon layer, and it can deliver a high discharge capacity of 161 mA h g−1 at 0.05C. At a 0.5C discharge rate, the LiMn0.8Fe0.2PO4/C can maintain 80.4% of its initial capacity after 900 cycles, and it also maintains 90% and 83% of its initial capacity at 45 °C and 55 °C respectively after 100 cycles. The results demonstrate that the modified polyol process is feasible for Fe-doping and carbon-coating to enhance the electrochemical performance of LiMnPO4.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Jugong Zheng,Liang Ni,Yanwen Lu,Cancan Qin,Panxing Liu,Tongfu Wu,Yuefeng Tang,Yanfeng Chen
LiMnPO 4 is proposed as more promising cathode material as LiFePO 4 , while poor electronic conductivity and Jahn-Teller effects during charge/discharge processes hinder the electrochemical performance. To overcome these problems, one-step solid state reaction method is developed to synthesize LiMnPO 4 /C composites, which is with nanostructure , high crystallinity and good carbon coating. Manganese oxide sources and calcination temperature are investigated as factors for preparing high-performance LiMnPO 4 /C for Li-ion batteries. The results show that the LiMnPO 4 /C composites prepared with mixed manganese oxide deliver a superior initial capacity of 153 mAh g −1 at 0.05 C and high rate performance with discharge capacities of 123 mAh g −1 at 1 C and 103 mAh g −1 at 2 C. And the LiMnPO 4 /C composites synthesized at 600 °C can retain 94% of the initial capacity after 200 cycles at 1 C, revealing a stable cycling stability. Therefore, one-step solid state reaction brings to light the synthesis of high performance LiMnPO 4 /C cathode materials and is suitable for large scale production.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CARBON
·
2019
·
IF 7.466
Hao Yang,Cuimei Fu,Yijian Sun,Lina Wang,Tianxi Liu
Olivine-type LiMnPO 4 (LMP) cathodes have gained enormous attraction for Li-ion batteries (LIBs) due to high discharge platform, theoretical capacity and thermal stability. However, it is still challenging to achieve encouraging Li-storage behavior owing to the low electronic conductivity and slow Li-ion diffusion rate of LMP. Here, the electrochemical behavior of fibrous LiFe x Mn 1-x PO 4 @carbon (LF x M 1-x P@C, x = 0, 0.25, 0.5, 0.75, 1) composites with different Fe doping amounts is investigated. Among the composites, LF 0.5 M 0.5 P@C demonstrates a superior cell performance due to a higher Li-ion diffusion coefficient (D Li ), resulting from a proper Fe doping ratio and a more uniform morphology. At a current rate of 0.2 C (1 C = 170 mA g −1 ), the LF 0.5 M 0.5 P@C cathode delivers a specific capacity of 150 mAh g −1 up to 500 cycles with a capacity retention of 119%. A longer-term cycling at 5 C for 2000 cycles can be maintained with a reversible capacity exceeding 102 mAh g −1 . The fundamental study provides an insightful guidance for future design of cathode materials with high performance.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Chao Wang,Shiheng Li,Yuyao Han,Zhenda Lu
A novel structure of a carbon-coated LiMnPO4 microcluster through emulsion-based self-assembly has been fabricated to yield a high-performance battery cathode. In this rational design, nanosized LiMnPO4 plates are assembled into microclusters to achieve a dense packing and robust interparticle contact. In addition, the conductive carbon framework wrapping around these clusters functions as a fast electron highway, ensuring the high utilization of the active materials. The designed structure demonstrates enhanced specific capacity and cycling stability in lithium-ion batteries, delivering a discharge capacity of 120 mAh g–1 after 200 cycles at 0.2 C. It also shows a superior rate capability with discharge capacities of 139.7 mAh g–1 at 0.05 C, 131.7 mAh g–1 at 0.1 C, and 99.2 mAh g–1 at 1 C at room temperature.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 29
·15299-15306
·
IF 7.443
Jugong Zheng,Cancan Qin,Tongfu Wu,Shuangfei Xie,Liang Ni,Muyang Peng,Yuefeng Tang,Yanfeng Chen
Preparing high-performance LiMnPO4 is still a large obstacle due to its sluggish electrochemical kinetics. To overcome this problem, a novel method is developed for LiMnPO4/C nanoplates from nanoporous Mn2O3 precursors. There are two advantages. Firstly, through negative pressure immersion, lithium dihydrogen phosphate (LiH2PO4), lithium hydroxide (LiOH) and sucrose (C12H22O11) are deposited on the surface of porous Mn2O3 nanosheets. In the following solid-state reaction, three dimensional continuous conductive carbon is wrapped uniformly around the LiMnPO4/C nanoplates, which greatly improved the conductivity. Secondly, (010) exposed facets are obtained using the Mn2O3 hierarchical microspheres as precursors, which allows for a fast transmission of Li+ ions improving the rate capability. As a result, the as-synthesized L-Mn2O3-LMP/C samples exhibit a superior rate performance with discharge capacities of 157.3 mA h g−1 at C/20, 122.6 mA h g−1 at 1C, and 105.8 mA h g−1 at 2C. Meanwhile, they can retain 99.3% of the initial capacity after 100 cycles at 1C, revealing an excellent cycling stability. This method sheds more light on the fabrication of high-performance LiMnPO4/C cathode materials and is suitable for large scale productions.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Wenhui Tu,Zewei Chen,Yuanpeng Cao,Jianguo Duan,Jingjing He,Runlin Li,Peng Dong,Xianshu Wang,Yingjie Zhang,Ding Wang
Olivine-structured LiMnPO 4 -based cathodes have generated enormous development prospects due to their high energy density , good structural stability , and low cost. However, their scale of application is limited by high electronic and ionic insulativity. In this study, we designed and synthesized a bi-functional interfacial modified composite, 0.9LiMnPO 4 @0.1LiFePO 4 /C ( [email protected] /C ), using mechanochemical activation-assisted hydrothermal technology. The innovative Li-storage structure consists of a high-energy density LiMnPO 4 (LMP) core, a uniformly coated LiFePO 4 (LFP) layer with improved ionic conductivity as the secondary outer shell, and an in-situ coated carbon film with high conductivity as the outermost functional skin. As anticipated, the [email protected] /C composite exhibits outstanding Li-storage properties, demonstrating discharge capacities as high as 157.1 mAh g −1 and 146.7 mAh g −1 at 0.1 C and 1 C rates, respectively. Moreover, it exhibits an ultrahigh capacity retention of 92.5 % after 500 charge and discharge cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Acta Metallurgica Sinica-English Letters
·
2021
·Vol. 35
·期 5
·790-800
·
IF 2.755
Yang Wei,Qiu Xiulian,Wang Chengyun,Ye Jinhao,Zhu Jihua,Zou Hanbo,Chen Shengzhou
An environmentally friendly method for the synthesis of LiMnPO 4 /C anode material for lithium-ion batteries by solvothermal method is introduced. The modification of the morphology of this precursor is altered by changing the ratio of the conditioning solvent (water-ethylene glycol solution) and the order of material addition. Ethylene glycol (EG) exerts a considerable influence on synthesizing LiMnPO 4 /C flake-like nanocrystal, which benefits the extraction/insertion reaction of lithium ions and improves the electrochemical activity and electrochemical performance of LiMnPO 4 /C material. When the solvent composition is H 2 O:EG = 1:3, exhibiting exceptional charge/discharge performance and rate capability, the specific discharge capacities are 155.8, 153.7, 148.8, 141.4, 129.5, and 112.6 mAh g −1 at the 0.1, 0.2, 0.5, 1, 2, and 5 C rates, respectively. When the charge–discharge rate returns to 0.1 C, the LiMnPO 4 /C material shows a reversible discharge specific capacity of 153.7 mAh g −1 . Differential scanning calorimetry (DSC) tests verify that the thermodynamic stability of the prepared LiMnPO 4 /C(LMP) and commercial LiFePO 4 (LFP)materials is better than that of commercial nickel–cobalt-aluminum (NCA) ternary materials. These prepared LiMnPO 4 /C composites have high electrochemical capacity and cycle stability.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 66
·39981-39987
·
IF 3.119
Ju-Gong Zheng,Guang-Yuan Ren,Jun Shi,Ting Yang,Yue-Feng Tang,Yan-Feng Chen
In this study, a facile yet efficient interfacial hydrothermal process was successfully developed to fabricate LiMnPO4/C composites. In this strategy, the walls of carbon nanotubes were employed as heterogeneous nucleation interfaces and biomass of phytic acid (PA) as an eco-friendly phosphorus source. By comparing the experimental results, a reasonable nucleation-growth mechanism was proposed, suggesting the advantages of interfacial effects. Meanwhile, the as-synthesized LiMnPO4/C samples exhibited superior rate performances with discharge capacities reaching 161 mA h g−1 at C/20, 134 mA h g−1 at 1C, and 100 mA h g−1 at 5C. The composites also displayed excellent cycling stabilities by maintaining 95% of the initial capacity over 100 continuous cycles at 1C. Electrochemical impedance spectroscopy showed that the superior electrochemical performances were attributed to the low charge-transfer resistance and elevated diffusion coefficient of lithium ions. In sum, the proposed approach for the preparation of LiMnPO4/C composites looks promising for future production of composite electrode materials for high-performance lithium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 49
·25625-25632
·
IF 3.708
Hua-Jun Zhu,Wei Zhai,Meng Yang,Xiao-min Liu,Yun-Chao Chen,Hui Yang,Xiao-dong Shen
Compared with LiFePO4, LiMnPO4 offers 20% higher energy density, but suffers from several orders lower electronic and ionic conductivity. The strategy usually adopted to overcome these intrinsic drawbacks is particle nanosizing mainly achieved by wet chemical methods or solid-state reactions in molten hydrocarbon, but which are not suitable for scale-up. A novel, economic and scalable method is proposed, using a T type micro-channel reactor to continuously precipitate nano-Mn3(PO4)2·3H2O for the first time. With the characterization of X-ray diffraction (XRD), transmission electron microscopy (TEM) and inductively coupled plasma (ICP), the generated Mn3(PO4)2·3H2O is proved to have an orthorhombic structure, a lath shape and possesses very high purity. The optimized temperature to prepare LiMnPO4/C nano-composites from the obtained Mn3(PO4)2·3H2O via a solid state reaction is proved to be 650 °C. The resulting sample is characterized by XRD, field emission scanning electron microscopy (FESEM), carbon/sulfur analysis, galvanostatic charge–discharge tests and alternating current impedance measurements. With 4.54 wt% of in situ carbon coating, this sample exhibits 137 mA h g−1 at 0.05 C and relatively good capacity retention. Moreover, by minimizing the impurities, the LiMnPO4 obtained from this novel method presents much improved Li+ diffusion coefficient due to less blocked [010] channels for Li+ migration.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2019
·Vol. 12
·期 16
·3817-3826
·
IF 7.804
Hao Yang,Jingyuan Liu,Xiaofei Wang,Chengcheng Zhao,Lina Wang,Yonggang Wang,Yongyao Xia,Tianxi Liu
Graphical Lithium storage : One-dimensional (1D) LiMnPO 4 @C nanofibers with in situ-created 3D mesoporous architecture are reported, and the charge-storage behavior is addressed. Remarkably, the hierarchical construction promotes the pseudocapacitive contributions. The diffusion-controlled battery-type and surface-controlled capacitive faradaic redox processes act synergistically, giving new insights into Li-storage cathode materials to reach the goal of high energy and power densities simultaneously. Olivine-structured LiMnPO 4 (LMP) is an efficient Li + host owing to its high theoretical energy density and thermal stability. However, its poor ionic and electronic conductivity severely hinder its practical application. Herein, one-dimensional (1D) LMP@C nanofibers with in situ created 3D mesoporous architecture are reported and the charge-storage behavior is addressed. Ultrafine LMP nanoparticles are homogeneously confined in the nanofibers with interconnected and exposed mesoporous intersections, facilitating the electronic/ionic transportation and retarding the pulverization/fracture of electrodes. Remarkably, the hierarchical construction promotes a certain degree of pseudocapacitive contribution. The diffusion-controlled battery-type and surface-controlled capacitive faradaic redox processes act synergistically, giving new insights into Li-ion storage cathode materials to reach the common goal of high energy density and power density simultaneously. The current separation technique suggests surface-dominated pseudocapacitance as the major Li + storage mechanism at high rates, which is regarded as an efficient way to improve the rate performance. Hence, the as-prepared LMP@C nanofibers could deliver a high reversible capacity of 149.8 mAh g −1 with 92 % charge retention over 300 cycles at 0.2 C (1 C=171 mA g −1 ). Even at a high rate of 5 C, a capacity of 63.1 mAh g −1 is retained after 2000 cycles with an exceptional cyclic stability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Jianguo Duan,Ceng Wu,Yanbing Cao,Ke Du,Zhongdong Peng,Guorong Hu
Abtract LiNi 0.80 Co 0.15 Al 0.05 O 2 has been widely pursued as an alternative to LiCoO 2 cathode materials for lithium ion batteries because of its high capacity and acceptable cycling property. However, that NCA can react with commercialized electrolyte during cycling restrains its wide use. Here, olivine structured LiMnPO 4 has been introduced to modify the surface of NCA by a sol-gel method. Characterizations from structure, morphology and composition analysis technologies demonstrate that a LiMnPO 4 layer has been uniformly coated on NCA particles. The electrochemical performance and thermo stability of modified samples are characterized by electrochemical tests, XRD and metallic nail penetration tests. The olivine structured skin, which provides structural and thermal stability, is used to encapsulate the high powered core via using the effective coating technique. The modified material displays a high discharge capacity of 211.0 mAh g −1 at 0.2 C and better rate performance and promoted cycling stability than the uncoated control sample. Furthermore, the thermal stability of coated sample in the delithiated state is upgraded to the pristine powders remarkably.
研究领域:
材料科学
·
电化学
·
储能
·
电池技术
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Fang-Jie Chen,Fen Tao,Chun-Mei Wang,Wen-Long Zhang,Li Chen
The CeO 2 /C hybrid coated LiMnPO 4 composites are prepared via a simple and effective wet chemical process followed by heat treatment at 550 °C. The nanometer-sized CeO 2 acts as an interconnector in carbon network, and its influence on the electrochemical performance is investigated in detail. The 0.25 wt.% CeO 2 -modified LiMnPO 4 /C (sample-0.25) exhibits the highest discharge capacity and the best cycle life, which can deliver an initial capacity of 139.9 mAh g −1 at 0.1C and still retain a reversible capacity of 120.4 mAh g −1 after 50 cycles (capacity retention of 86.1%). While for pristine LiMnPO 4 /C (sample-0), only 94.4 mAh g −1 can be obtained at the 50th cycle, corresponding to 72.9% of its initial discharge capacity (129.5 mAh g −1 ). Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) results confirm that an integrated and hybrid CeO 2 /C coating layer is formed on LiMnPO 4 surface and its existence has no influence on the structure of LiMnPO 4 . The reason for the improved electrochemical properties of the CeO 2 -modified LiMnPO 4 /C composites has also been studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）