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In this study, we are reporting the impact of the incorporation of ferroelectric nanoparticles (FNPs), such as BaTiO3 (BTO), BiFeO3 (BFO), Bi4NdTi3Fe0.7Ni0.3O15 (BNTFN), and Bi4NdTi3Fe0.5Co0.5O15 (BNTFC), as well as the mass loading of sulfur to fabricated solvent-free sulfur/holey graphene-carbon black/polyvinylidene fluoride (S/FNPs/CBhG/PVDF) composite electrodes to achieve high areal capacity for lithium-sulfur (Li-S) batteries. The dry-press method was adopted to fabricate composite cathodes. The hG, a conductive and lightweight scaffold derived from graphene, served as a matrix to host sulfur and FNPs for the fabrication of solvent-free composites. Raman spectra confirmed the dominant hG framework for all the composites, with strong D, G, and 2D bands. The surface morphology of the fabricated cathode system showed a homogeneous distribution of FNPs throughout the composites, confirmed by the EDAX spectra. The observed Li+ ion diffusion coefficient for the composite cathode started at 2.17 × 10−16 cm2/s (S25(CBhG)65PVDF10) and reached up to the highest value (4.15 × 10−15 cm2/s) for S25BNTFC5(CBhG)60PVDF10. The best discharge capacity values for the S25(CBhG)65PVDF10 and S25BNTFC5(CBhG)60PVDF10 composites started at 1123 mAh/gs and 1509 mAh/gs and dropped to 612 mAh/gs and 572 mAh/gs, respectively, after 100 cycles; similar behavior was exhibited by the other composites that were among the best. These are better values than those previously reported in the literature. The incorporation of ferroelectric nanoparticles in the cathodes of Li-S batteries reduced the rapid formation of polysulfides due to their internal electric fields. The areal capacity for the S25(CBhG)65PVDF10 composites was 4.84 mAh/cm2 with a mass loading of 4.31 mgs/cm2, while that for the S25BNTFC5(CBhG)60PVDF10 composites was 6.74 mAh/cm2 with a mass loading of 4.46 mgs/cm2. It was confirmed that effective FNP incorporation within the S cathode improves the cycling response and stability of cathodes, enabling the high performance of Li-S batteries.
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A simple and scalable pre-lithiation approach for high energy and low cost lithium ion sulfur batteries
Sulfur-polyacrylonitrile (S-PAN) composite has been developed as a novel composite cathode material to address many issues with conventional Li-S batteries (LSBs). In this study, a freestanding S-PAN-CNT composite is first developed as the cathode material for LSBs, which is capable to deliver a high specific capacity of 1458 mAh g-1 at 0.2C and a desirable high-rate performance of 1097 mAh g-1 at 2.0 C. Furthermore, a Li2S-PAN-CNT cathode is obtained via in-situ direct pre-lithiation of S-PAN-CNT composite, which exhibits an even improved discharge capacity, cycling performance, and rate capability. Lastly, we develop Li-ion sulfur full batteries based on both S-PAN-CNT and Li2S-PAN-CNT cathode. The excellent electrochemical performance and corresponding theoretical estimation both demonstrate that the proposed system as a promising metal-free Li-ion battery with a high specific capacity, good cycle life, and low cost.
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- Award ID(s):
- 1805288
- PAR ID:
- 10167527
- Date Published:
- Journal Name:
- Journal of the Electrochemical Society
- Volume:
- 167
- ISSN:
- 1945-7111
- Page Range / eLocation ID:
- 060517
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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