| 1. |
- Slawinski, Wojciech Andrzej, 1980, et al.
(författare)
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Neutron Pair Distribution Function Study of FePO4 and LiFePO4
- 2019
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 1520-5002 .- 0897-4756. ; 31:14, s. 5024-5034
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Tidskriftsartikel (refereegranskat)abstract
- Neutron powder diffraction studies of the compounds FePO4 and LiFePO4 are reported. Rietveld refinement of the diffraction data provides averaged structures for both materials that are in good agreement with the published structures. In addition, detailed investigations of the short-range ion-ion correlations within each compound have been performed using the reverse Monte Carlo (RMC) modeling of the total scattering (Bragg plus diffuse) data. Although the short-range structural information for LiFePO4 is consistent with the long-range (averaged) picture, a small, but statistically significant, proportion of the anions is displaced away from their ideal sites within the RMC configurations of FePO4. These anion displacements are discussed in terms of a small concentration of Li+/Fe2+ occupying the empty octahedral sites, probably arising from incomplete delithiation of the LiFePO4 and/or antisite (Li+-Fe2+) defects introduced during the delithiation process.
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| 2. |
- Heintz, Mads C., et al.
(författare)
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Photovoltaic Wafering Silicon Kerf Loss as Raw Material : Example of Negative Electrode for Lithium‐Ion Battery
- 2023
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Ingår i: ChemElectroChem. - : Wiley-VCH Verlagsgesellschaft. - 2196-0216. ; 10:19
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Tidskriftsartikel (refereegranskat)abstract
- Silicon powder kerf loss from diamond wire sawing in the photovoltaic wafering industry is a highly appealing source material for use in lithium-ion battery negative electrodes. Here, it is demonstrated for the first time that the kerf particles from three independent sources contain ~50 % amorphous silicon. The crystalline phase is in the shape of nano-scale crystalline inclusions in an amorphous matrix. From literature on wafering technology looking at wafer quality, the origin and mechanisms responsible for the amorphous content in the kerf loss powder are explained. In order to better understand for which applications the material could be a valuable raw material, the amorphicity and other relevant features are thoroughly investigated by a large amount of experimental methods. Furthermore, the kerf powder was crystallized and compared to the partly amorphous sample by operando X-ray powder diffraction experiments during battery cycling, demonstrating that the powders are relevant for further investigation and development for battery applications.
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| 3. |
- Xu, Chao, 1988-, et al.
(författare)
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The Role of LiTDI Additive in LiNi1/3Mn1/3Co1/3O2/ Graphite Lithium-Ion Batteries at Elevated Temperatures
- 2018
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Ingår i: Journal of the Electrochemical Society. - : ELECTROCHEMICAL SOC INC. - 0013-4651 .- 1945-7111. ; 165:2, s. A40-A46
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Tidskriftsartikel (refereegranskat)abstract
- The poor thermal stability of conventional LiPF6-based electrolytes is one of the major obstacles for today's lithium-ion batteries. Recently, lithium 4,5-dicyano-2-( trifluoromethyl) imidazolide (LiTDI) has demonstrated to be highly efficient in scavenging moisture from the electrolyte and thereby improving electrolyte stability. In this context, effects of the LiTDI additive on LiNi1/3Mn1/3Co1/3O2 (NMC)/graphite cells are evaluated at a temperature of 55 degrees C. With the incorporation of LiTDI, an improved cycling performance of NMC/graphite cells was achieved, and the impedance increase at the NMC/electrolyte interface was significantly mitigated. Furthermore, LiTDI exhibited a profound influence on the interfacial chemistries in the full cell, and LiTDI-derived species were found on the surfaces of both the cathode and the anode. The SEI layer formed on graphite anodes was more homogenous in morphology and consisted of larger amounts of LiF and fewer oxygen-containing species, as compared to graphite in additive-free cells. This study shows that LiTDI is a promising electrolyte additive for NMC/graphite cells operated at elevated temperatures, highlighting that the influence of the LiTDI additive is worth exploring also in other battery chemistries.
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| 4. |
- Zhang, Leiting, et al.
(författare)
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Reversible Hydration Enabling High-Rate Aqueous Li-Ion Batteries
- 2024
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Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 9, s. 959-966
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Tidskriftsartikel (refereegranskat)abstract
- Layered TiS2 has been proposed as a versatile host material for various battery chemistries. Nevertheless, its compatibility with aqueous electrolytes has not been thoroughly understood. Herein, we report on a reversible hydration process to account for the electrochemical activity and structural evolution of TiS2 in a relatively dilute electrolyte for sustainable aqueous Li-ion batteries. Solvated water molecules intercalate in TiS2 layers together with Li+ cations, forming a hydrated phase with a nominal formula unit of Li0.38(H2O)2−δTiS2 as the end-product. We unambiguously confirm the presence of two layers of intercalated water by complementary electrochemical cycling, operando structural characterization, and computational simulation. Such a process is fast and reversible, delivering 60 mAh g–1 discharge capacity at a current density of 1250 mA g–1. Our work provides further design principles for high-rate aqueous Li-ion batteries based on reversible water cointercalation.
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