JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Liling Yi,Gang Wang,Yansong Bai,Meihong Liu,Xuan Wang,Min Liu,Xianyou Wang
The morphology-controlled Li 2 FeSiO 4 /C cathode material is successfully synthesized by a sol-gel method, in which commercial, spherical and cubic Fe 2 O 3 are respectively used as iron sources. By controlling the Fe 2 O 3 precursors' morphologies, the morphology and grain size of the Li 2 FeSiO 4 /C materials can be purposefully controlled via morphology-inheritance strategy. The morphologies, sizes, elemental distributions and structures of the as-prepared Li 2 FeSiO 4 /C materials are confirmed by field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). The results show that the as-synthesized Li 2 FeSiO 4 /C samples exhibit well-defined morphologies due to the homogeneous and well-crystallized Fe 2 O 3 precursors. Comparing with Li 2 FeSiO 4 /C synthesized by commercial Fe 2 O 3 precursor, the Li 2 FeSiO 4 /C materials prepared by spherical or cubic Fe 2 O 3 precursors exhibit eminent electrochemical properties , e.g., high initial reversible capacities of 214.1 mAh g −1 for LFS/C-S and 206.5 mAh g −1 for LFS/C-C at 0.1 C and good cyclic stability (93.1% for LFS/C-S and 91.5% for LFS/C-C). In particular, the spherical LFS/C-S material with better fluidity and less agglomeration displays excellent rate capability of 105.4 mAh g −1 at 10 C. Therefore, the control of the morphology and size during preparation process of Li 2 FeSiO 4 /C cathode materials will open a new route for the development of high performances lithium-ion batteries.
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
·
2018
·
IF 3.779
Qingtang Zhang,Chao Yan,Yan Meng,Xiaomei Wang
Hierarchical mesoporous Li 2 FeSiO 4 /C sheaf-rods (HMLFS-SRs) were fabricated using a hard template method with SBA-15 as a silicon source. For comparision, Li 2 FeSiO 4 /C nanocomposites (LFS) were prepared using nano-SiO 2 under the same conditions. XRD results prove that both the HMLFS-SRs and LFS contain crystalline Li 2 FeSiO 4 and trace amounts of Fe 3 O 4 impurities. The SEM and TEM images indicate that the HMLFS-SRs are hierarchical sheaf rods composed of nanoparticles . EDS data prove that elemental Fe, Si, O and C are uniformly distributed throughout the whole Li 2 FeSiO 4 /C sheaf rod. Nitrogen adsorption/desorption analyses further indicate that the HMLFS-SRs are typical mesoporous materials with an external surface area of 47 m 2 g −1 , which is higher than that of the LFS (31 m 2 g −1 ). These unique structures enable the HMLFS-SRs to exhibit much better electrochemical performance than the LFS. The HMLFS-SRs deliver a high discharge capacity of 206.6 mAh g −1 at 0.1 C. In addition, the HMLFS-SRs also have good cycling performance, satisfactory rate performance, a low charge transfer resistance and a large lithium-ion diffusion coefficient .
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qingtang Zhang,Xiaoyu Wu,QiQi Shu,Ce Su,Xiaomei Wang
Nano porous Li 2 FeSiO 4 /C composite (LFS-10S) was prepared by KOH selective etching Li 2 FeSiO 4 -(SiO 2 ) 0.1 /C composites. This method allows directly pore-creating on Li 2 FeSiO 4 crystal. Common porous Li 2 FeSiO 4 /C (LFS) were also prepared as a control. LFS-10S and LFS were characterized by XRD, SEM, TEM and nitrogen adsorption/desorption test. XRD analysis shows that the LFS-10S material was composed of crystalline particles with a monoclinic crystal system in the P 2 1 space group. SEM and TEM tests indicate that the particle size of LFS-10S is 20 ∼ 30 nm. The nitrogen adsorption/desorption test shows that the specific surface area of LFS-10S is 123.23 m 2 /g, larger than that of LFS (71.56 m 2 /g). These features make LFS-10S exhibit better electrochemical performance over LFS. The specific discharge capacity of LFS-10S at 0.1 C is as high as 235.2 mA h g −1 , higher than that of LFS (158.4 mA h g −1 ). Moreover, the rate performance, cycling performance and lithium ion diffusion coefficient of LFS-10S are all better than those of LFS.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
VACUUM
·
2019
·
IF 2.515
Kun Wang,Xiaobing Huang,Tao Zhou,Haiyan Wang,Huasheng Xie,Yurong Ren
Li 2 FeSiO 4 /C cathode composites were fabricated from a simple solid-state approach using precursor Fe-MOFs prepared by hydrothermal process. The Li 2 FeSiO 4 /C composites covered by carbon film with diverse contents were characterized using XRD , SEM , galvanostatic charge-discharge measurement and EIS, and so on. Results of the investigation prove that Li 2 FeSiO 4 /C composites with 19.3 wt % carbon layer present prominent electrochemical capability, which delivered the discharge capacity of 154, 138, 129, 117 and 100 mA h g −1 at 0.2, 0.5, 1, 2 and 5 C, respectively. After 100 cycles, discharge capacity retained 97.4% compared to the original value at 2 C. Furthermore, it possesses the lowest charge transfer resistance as well as the highest Li + diffusion coefficient , attributing to uniform carbon coating and porous structure for Li 2 FeSiO 4 /C composites.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2018
·Vol. 12
·期 2
·357-363
·
IF 7.994
Shen Shuiyun,Zhang Yao,Wei Guanghua,Zhang Wansen,Yan Xiaohui,Xia Guofeng,Wu Aiming,Ke Changchun,Zhang Junliang
Undoubtedly, it is imperative to figure out two stubborn issues concerning low electronic conductivity and sluggish lithium ion diffusion to promote the practical application of Li 2 FeSiO 4 materials in lithium-ion battery (LIB) cathode. Herein, we report an innovative and simple strategy that combines a hydrothermal process with subsequent annealing to synthesize highly uniform Li 2 FeSiO 4 /C hollow nanospheres. During the hydrothermal process, polystyrene nanospheres are employed not only as the template but also, more tactfully, as carbon source to form amorphous carbon layers, which will function to enhance the electronic conductivity and restrict particle aggregations. The use of the LIB Li 2 FeSiO 4 /C hollow nanospheres as a LIB cathode delivers a desired stable capacity at each rate stage, and even at a high rate of 10 C, the hollow nanosphere cathode can present a specific discharge capacity as high as 50.5 mAh·g −1 . After 100 cycles, the capacity retentions at 1 and 10 C remain as high as 93% and 72%, respectively. The superior electrochemical performance is believed to be related to special architectures of the Li 2 FeSiO 4 /C hollow nanosphere cathode.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2017
·Vol. 24
·期 9
·2555-2563
·
IF 2.062
Zhang Qingtang,Yan Chao,Guo Junhong,Wang Xiaomei
Mesoporous Li 2 FeSiO 4 /C nanocomposites (LFS-FNS and LFS-NS) were prepared from fumed nano silica (FNS) and nano silica (NS) through facile solid-state reactions, respectively. XRD analysis indicates that the crystalline structures of LFS-FNS and LFS-NS are indexed to monoclinic Li 2 FeSiO 4 of P2 1 . SEM results prove that the particle size of LFS-FNS and FNS (25~40 nm) is smaller than that of LFS-NS and NS, revealing the particle size of Li 2 FeSiO 4 /C nanocomposites can be tuned by choosing different silica. TEM further indicates Li 2 FeSiO 4 nanoparticles are uniformly dispersed in the amorphous carbon networking of LFS-FNS. Pore structure analysis indicates the external surface areas of LFS-FNS as well as LFS-NS are 51.4 and 36.1 m 2 g −1 , indicating the pore properties of mesoporous Li 2 FeSiO 4 /C nanocomposites can be controlled by using different silica as silicon resource. The reduced particle size and high external surface area shorten the lithium-ion diffusion path and make LFS-FNS possess better electrochemical performance over LFS-NS. The discharge capacity of LFS-FNS is as high as 172 mA h g −1 at 0.1 C.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 4
·808
·
IF 4.6
Jinhai Cui,Dezhi Chen,Mengna Xie,Yongheng Zhou,Shuai Dong,Wei Wei
One method to enhance the electrochemical performance of carbon-coated Li2FeSiO4cathode material in lithium-ion batteries is to produce an ideal Li2FeSiO4precursor with minimal impurities. A novel precursor for Li2FeSiO4(Li2O·FeCO3·CH3OSiO2H) was synthesized through a methanol solvothermal reaction under stringent conditions (180 °C and 2.7 MPa), achieving a purity level of 93.2%. During synthesis, the new Li2FeSiO4precursor exhibits unique self-purification properties and maintains a fine morphology after annealing. The resulting carbon-coated Li2FeSiO4composites demonstrate a Brunauer–Emmett–Teller specific surface area of 102.4 m2/g and approximately 81% mesoporous volume, with 90% of the pore sizes measuring less than 39 nm. As a cathode material for lithium-ion batteries, this carbon-coated Li2FeSiO4exhibits initial specific capacities of 172.3 mAh/g (charge) and 159.3 mAh/g (discharge). Remarkably, nearly 50% of the theoretical specific capacity remains after 1300 cycles at a rate of 0.1 C. The excellent electrochemical performance of the carbon-coated Li2FeSiO4materials is demonstrated by their high lithium-ion diffusivity (DLi+) value of 1.26 × 10−11cm2/s. Additionally, the enormous capacities-controlled diffusion contribution, which accounts for 70% of the total diffusion at a rate of 1C, is noteworthy. This performance can be attributed to the high purity of the carbon-free Li2FeSiO4composite, which contains 91% Li2FeSiO4, as well as its favorable morphology.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS TECHNOLOGY
·
2021
·
IF 3.846
Qingtang Zhang,Shaokang Ji,Chao Yan,Xiaomei Wang
Nano-Li2FeSiO4/C composites (LFS/C-325 and LFS/C-221) and nano-Li2FeSiO4 (LFS-325 and LFS-221) with controlled porosity were prepared from the nano-fumed silicas with similar particle size and different porosity. N2 adsorption/desorption analysis reveals that the porosity of nano-Li2FeSiO4/C composites and nano-Li2FeSiO4 can be tuned by the choosing nano -fumed silica and LFS/C-325 possess the highest specific surface area among the four samples. XRD indicates that both LFS/C-325 and LFS/C-221 are crystalline powders with monoclinic Li2FeSiO4 of P21. FTIR spectra show that Li-O and Si-O bonds are existed in the four samples. SEM images demonstrate that LFS/C-325 and LFS/C-221 have similar particle sizes in the range of 20 ~ 25 nm, which are distinctly smaller than those of LFS-325 and LFS-221. LFS/C-325 features the smallest particle size and largest specific area, which enables LFS/C-325 to exhibit the best electrochemical performance. The initial discharge capacity of LFS/C-325 is as high as 185.2 mAh g−1 at 0.1 C.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2015
·
IF 2.561
Xiaobing Huang,Yaoyao You,Yurong Ren,Haiyan Wang,Yuandao Chen,Xiang Ding,Beiping Liu,Shibiao Zhou,Fuqiang Chu
Improving the rate performance is still a major challenge for Li 2 FeSiO 4 cathode material for Li-ion battery. Herein, hollow spherical Li 2 FeSiO 4 /C microscale particles, consisting of carbon-coated primary nanoparticles (20–40 nm) have been fabricated by a spray drying-assisted method. The particle size of spherical Li 2 FeSiO 4 /C is 1–5 μm, which is suitable for commercial application. When used as a cathode material for Li-ion battery, the as-prepared Li 2 FeSiO 4 /C composite with 16.7 wt.% carbon exhibits a high discharge capacity of 165 mAh g − 1 at 0.2 C rate. At 0.5 C, 5 C and 10 C rates, the capacities of 151 mAh g − 1 , 111 mAh g − 1 , and 96 mAh g − 1 are observed, respectively, indicating superior rate performance. Meantime, good cycling stability is achieved with a capacity retention of 94.5% at a high current density of 2 C after 100 cycles. The excellent electrochemical performance is mainly ascribed to the improved ionic/electronic conductivity arising from the hollow spherical structure and carbon-coated primary nanoparticles . The spray drying process shows a great potential for the large scale production of high quality Li 2 FeSiO 4 /C composite.
研究领域:
材料科学
·
电化学
·
储能技术
·
纳米材料
·
锂离子电池
✓ 已验证
DOI
高影响因子
Journal of Central South University
·
2019
·Vol. 26
·期 6
·1443-1448
·
IF 0.973
Tang Yi-qun,Liu Xi,Huang Xiao-bing,Ding Xiang,Zhou Shi-biao,Chen Yuan-dao
Li 2 FeSiO 4 is deemed to be a potential candidate for large-scale applications because of its abundance, low cost and high safety, etc. Unfortunately, its low conductivity, resulting in poor rate performance, has become a main obstacle to its applications in power battery and energy storage system. In this work, C-Ag coated Li 2 FeSiO 4 is introduced to improve the innate electronic conductivity and Li-ion diffusion ability. The results demonstrate that Li 2 FeSiO 4 /C/Ag composite exhibits better electrochemical performance. It possesses a specific discharge capacity of 152, 121, 108 mA∙h/g at 0.2 C , 5 C and 10 C , respectively. At the same time, the Li 2 FeSiO 4 /C/Ag composite shows good cycle stability and a capacity retention ratio of 97.9% after 100 cycles at 1 C .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）