29 research outputs found
Experimental Measurements of Electron Stopping Power at Low Energies
The electron stopping power has been measured for twelve elements and fifteen compounds, over the energy range from 1 eV to 10 keV, by the analysis of electron energy loss spectra, optical data, and photon mass absorption data. Values of the effective mean ionization potential Jeff and the effective number of participating electrons Neff have also been determined in each case. The results obtained have been compared with other experimental data, with first-principles theoretical calculations, and with a number of proposed analytical models
Cation exchange mediated elimination of the Fe-antisites in the hydrothermal synthesis of LiFePO 4
Olivine-Based Blended Compounds as Positive Electrodes for Lithium Batteries
Blended cathode materials made by mixing LiFePO4 (LFP) with LiMnPO4 (LMP) or LiNi1/3Mn1/3Co1/3O2 (NMC) that exhibit either high specific energy and high rate capability were investigated. The layered blend LMPâLFP and the physically mixed blend NMCâLFP are evaluated in terms of particle morphology and electrochemical performance. Results indicate that the LMPâLFP (66:33) blend has a better discharge rate than the LiMn1âyFeyPO4 with the same composition (y = 0.33), and NMCâLFP (70:30) delivers a remarkable stable capacity over 125 cycles. Finally, in situ voltage measurement methods were applied for the evaluation of the phase evolution of blended cathodes and gradual changes in cell behavior upon cycling. We also discuss through these examples the promising development of blends as future electrodes for new generations of Li-ion batteries
Schiff Base as Additive for Preventing Gas Evolution in Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>-Based Lithium-Ion Battery
Lithium
titanium oxide (Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>)-based
electrodes are very promising for long-life cycle batteries. However,
the surface reactivity of Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> in organic electrolytes leading to gas evolution is still a problem
that may cause expansion of pouch cells. In this study, we report
the use of Schiff base (1,8-diazabicyclo[5.4.0]Âundec-7-ene) as an
additive that prevents gas evolution during cell aging by a new mechanism
involving the solid electrolyte interface on the anode surface. The
in situ ring opening polymerization of cyclic carbonates occurs during
the first cycles to decrease gas evolution by 9.7 vol % without increasing
the internal resistance of the battery