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Kumar A, Jayakumar OD, Jagannath, Bashiri P, Nazri GA, Naik VM, Naik R. Mg doped Li 2FeSiO 4/C nanocomposites synthesized by the solvothermal method for lithium ion batteries. Dalton Trans 2017; 46:12908-12915. [PMID: 28926060 DOI: 10.1039/c7dt03177g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of porous Li2Fe1-xMgxSiO4/C (x = 0, 0.01, 0.02, 0.04) nanocomposites (LFS/C, 1Mg-LFS/C, 2Mg-LFS and 4Mg-LFS/C) have been synthesized via a solvo-thermal method using the Pluronic P123 polymer as an in situ carbon source. Rietveld refinement of the X-ray diffraction data of Li2Fe1-xMgxSiO4/C composites confirms the formation of the monoclinic P21 structure of Li2FeSiO4. The addition of Mg facilitates the growth of impurity-free Li2FeSiO4 with increased crystallinity and particle size. Despite having the same percentage of carbon content (∼15 wt%) in all the samples, the 1Mg-LFS/C nanocomposite delivered the highest initial discharge capacity of 278 mA h g-1 (∼84% of the theoretical capacity) at the C/30 rate and also exhibited the best rate capability and cycle stability (94% retention after 100 charge-discharge cycles at 1C). This is attributed to its large surface area with a narrow pore size distribution and a lower charge transfer resistance with enhanced Li-ion diffusion coefficient compared to other nanocomposites.
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Affiliation(s)
- Ajay Kumar
- Department of Physics and Astronomy, Wayne State Physics, Detroit, USA.
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Li D, Zhang W, Sun R, Yong HTH, Chen G, Fan X, Gou L, Mao Y, Zhao K, Tian M. Soft-template construction of three-dimensionally ordered inverse opal structure from Li2FeSiO4/C composite nanofibers for high-rate lithium-ion batteries. NANOSCALE 2016; 8:12202-14. [PMID: 27251876 DOI: 10.1039/c5nr07783d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Exploring a new method to fabricate small-sized nanofibers is essential to achieve superior performances for energy conversion and storage devices. Here, a novel soft-template strategy is developed to synthesize a three-dimensionally ordered macroporous (3DOM) architecture constructed from small-sized nanofibers. The effectiveness of a nanofiber-assembled three-dimensional inverse opal material as an electrode for high-rate lithium-ion batteries is demonstrated. The small-sized Li2FeSiO4/C composite nanofibers with a diameter of 20-30 nm are grown by employing a tri-block copolymer P123 as a structure directing agent. Accordingly, the macro-mesoporous hierarchical 3DOM architecture constructed from Li2FeSiO4/C nanofibers is further templated from P123 for the nanofibers and a polystyrene colloidal crystal array for the 3DOM architecture. We find that the thermal stability of the nanofiber morphology depends on the self-limited growth of Li2FeSiO4 nanocrystals in a crystalline-amorphous hybrid. As a cathode for a lithium-ion battery, the 3D hierarchical macro-mesoporous cathodes exhibit outstanding high-rate and ultralong-life performances with a capacity retention of 84% after 1500 cycles at 5 C in the voltage window of 1.5-4.5 V, which is greatly improved compared with a simple 3DOM Li2FeSiO4/C nanocomposite.
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Affiliation(s)
- Donglin Li
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Wei Zhang
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Ru Sun
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Hong-Tuan-Hua Yong
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Guangqi Chen
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Xiaoyong Fan
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Lei Gou
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Yiyang Mao
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Kun Zhao
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
| | - Miao Tian
- New Energy Materials and Device Laboratory, School of Materials Science and Engineering, Chang'an University, Xi'an, 710064, China.
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