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[en] Highlights: • Ni/NiO anodes are processed by electrodeposition NiO from ionic liquids • Annealed Ni/NiO-electrode provides enhanced specific capacity and stable cyclability • NiO sub-layer, formed by thermal oxidation, is the main origin of capacity increase • Electrochemical performance of Ni/NiO anodes was evaluated in half and full cells - Abstract: An innovative route to obtain Ni/NiO core-shell foam-based anodes for lithium-ion batteries is presented. Commercial Ni foams are conformally coated with NiO by ionic liquid-based electrodeposition. The electrochemical behavior of the resulting Ni/NiO electrodes in half coin cells with lithium counter electrode is investigated. The results are qualitatively correlated to the microstructural properties, including effects of the thermal annealing at 500 °C, of the NiO shell. The formation a NiO sub-layer by the thermal oxidation of the Ni foam seems to play a crucial role in the enhanced performance of the annealed Ni/NiO anodes, which exhibit a reversible discharge capacity around 0.8 mAh/cm"2. Furthermore, the Ni/NiO core-shell foam-based anodes are evaluated in full coin Li-ion cells with high voltage LiMn_0_._8Fe_0_._2PO_4 cathode. Promising cyclability is reached in NiO-LMFP coin cells under cycling at 0.4C.
[en] Highlights: • Importance of mixing intensity for aqueous LiFePO4 cathode slurries is demonstrated. • Fe3+ rich layer formation on intensively mixed LiFePO4 electrode surface is detected. • C/LiFePO4 pouch cells with aqueous processed electrodes show outstanding cyclability. • Aqueous cathode slurry processing is viable approach toward cheaper and greener LIBs. - Abstract: The positive electrodes based on nano- and micrometric carbon coated LiFePO4 (LFP) powders are prepared via aqueous slurry processing using “normal” and “intensive” mixing procedures. The XRD, XPS, and electrochemical characterization reveal that the “intensive” mixing process improves the discharge C-rate capability of the n-LFP cathode however provokes formation of an undesirable thin surface layer enriched by Fe3+ species. The waterborne graphite anodes and LiFePO4 cathodes for the energy and power cells are being developed, upscaled and manufactured on a pilot plant. Energy LiFePO4/C pouch cells demonstrate outstanding durability maintaining 80% of initial discharge capacity (IDC) after 7450 and 2400 full cycles under 1D and 4D discharge currents, respectively. Moreover, further cycling of the energy cell working under 1C/4D protocol reveals its extra-long secondary life (70% of IDC on 9200th cycle). Power LiFePO4/C pouch cell shows long lasting cycle life retaining 80% of IDC after 3350 cycles under harsh cycling conditions (3C/8D). The reported results are being achieved despite confirmed water release from lithium iron phosphate cathodes to the electrolyte. Finally, viability of aqueous processing of the electrodes without sacrificing electrochemical performance of LiFePO4/C batteries is clearly proven.
[en] This paper presents an increase to x = 0.67 of the zirconium content in the conductive Bi2-xZrxO3+δ solid solution. Complete incorporation of Zr in the βIII-Bi2O3 structure, confirmed by X-ray powder diffraction, has produced a phase with a lower volume and superior conductivity than those predicted by an earlier study. The observed βIII-δ Bi2-xZrxO3+δ phase transition around 730 deg. C has been characterised for the first time and shows a segregation of a mixture of predominantly γ-Bi2O3 and approximately 30% of the ZrO2, before total reincorporation of the Zr in the high temperature δ-phase