Capture of carbon dioxide over porous solid adsorbents lithium silicate, lithium aluminate and magnesium aluminate at pre-combustion temperatures

The capturing process for carbon dioxide over porous solid adsorbents such as lithium silicate,lithium aluminate,and magnesium aluminate at pre-combustion temperatures was studied.Lithium silicate was prepared by the sol gel and solid fusion methods.The lithium silicate adsorbent was characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning elec-tron microscopy(SEM),nuclear magnetic resonance(NMR),and surface area.The capturing of carbon dioxide over lithium silicate,lithium aluminate,and magnesium aluminate was explored at different experimental condi-tions such as exposure time,temperature variation,and exposure carbon dioxide pressure.The capturing process for carbon dioxide was investigated over these adsorbents with variation of their metal mole ratios.The effect of the addition of(promoter)sodium,potassium,and cesium in the lithium silicate adsorbent was explored to investigate the variation of the capture of carbon dioxide over these adsorbents.

Transparent PVDF-based electrolyte enabled by lipophilic lithium magnesium silicate for solid-state lithium batteries

Solid-state batteries with solid polymer electrolytes are considered the most promising due to their high energy density and safety advantages.However,their development is hindered by the limitations of polymer electrolytes,such as low ionic conductivity,poor mechanical strength and inadequate fire resistance.This study presents a thin polyvinylidene fluoride-based composite solid electrolyte film(25μm incorporating twodimensional modified lipophilic lithium magnesium silicate(LLS)as additives with good dispersibility.The incorporation of LLS promotes grain refinement in polyvinylidene fluoride(PVDF),enhances the densification of electrolyte films,increases the tensile strength to10.42 MPa and the elongation to 251.58%,improves ion transport interfac e,and facilitates uniform deposition of lithium ions.Furthermore,LLS demonstrates strong adsorption ability,promoting the formation of solvated molecules,resulting in high ionic conductivity(2.07×10^(-4)S·cm^(-1)at 30℃)and a stable lithium/electrolyte interface.Symmetric Li//Li cells assembled with the thin composite electrolytes exhibit stable cycling for2000 h at 0.1 mA·cm^(-2)and 0.05 mAh·cm^(-2).Additionally,the LiFePO_(4)//Li battery shows a capacity retention rate of99.9%after 200 cycles at 0.5C and room temperature.

Brain-like synaptic memristor based on lithiumdoped silicate for neuromorphic computing

Artificial synapse is one of the potential electronics for constructing neural network hardware.In this work,Pt/LiSiO_(x)/TiN analog artificial synapse memristor is designed and investigated.With the increase of compliance current(C.C.)under 0.6 mA,1 mA,and 3 mA,the current in the high resistance state(HRS)presents an increasing variation,which indicates lithium ions participates in the operation process for Pt/LiSiO_(x)/TiN memristor.Moreover,depending on the movement of lithium ions in the functional layer,the memristor illustrates excellent conduction modulation property,so the long-term potentiation(LTP)or depression(LTD)and paired-pulse facilitation(PPF)synaptic functions are successfully achieved.The neural network simulation for pattern recognition is proposed with the recognition accuracy of 91.4%.These findings suggest the potential application of the LiSiO_(x)memristor in the neuromorphic computing.

Evaluation of leaching characteristic and kinetic study of lithium from lithium aluminum silicate glass-ceramics by NaOH

The behavior and mechanism of Li leaching from lithium aluminum silicate glass-ceramics which can be used as a secondary source of Li using aqueous NaOH solution was investigated.The Li leaching efficiency is increased with increasing concentration of NaOH, specific surface area, and reaction temperature.When leached under optimum conditions, 2 mol/L NaOH, 53 μm particle undersize, 1:10 solid/liquid ratio, 250 r/min stirring speed, 100℃ reaction temperature, 12 hr, the Li leaching efficiency was approximately 70%.However, when the leaching experiment was performed for 48 hr, the concentration of Li+ ions contained in the leach liquor decreased from 1160 to 236 mg/L.To investigate the origin of this phenomenon, the obtained leach residue was analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy.These analyses show that zeolite was formed around the lithium aluminum silicate glass-ceramics, which affected the leaching of by adsorbing Li+ ions.In addition, using the shrinking-core model and the Arrhenius equation, the leaching reaction with NaOH was found to depends on the chemical reaction of the two reactants, with a higher than 41.84 kJ/mol of the activation energy.

Carbon nanotube directed three-dimensional porous Li2FeSiO4 composite for lithium batteries

Lithium iron silicate （Li2FeSiO4） is capable of affording a much higher capacity than conventional cathodes, and thus, it shows great promise for high-energy battery applications. However, its capacity has often been adversely affected by poor reaction activity due to the extremely low electronic and ionic conductivity of silicates. Here, we for the first time report on a rational engineering strategy towards a highly active Li2FeSiO4 by designing a carbon nanotube （CNT） directed three-dimensional （3D） porous Li2FeSiO4 composite. As the CNT framework enables rapid electron transport, and the rich pores allow efficient electrolyte penetration, this unique 3D Li2FeSiO4-CNT composite exhibits a high capacity of 214 mAh·g^-1 and retains 96% of this value over 40 cycles, thus, outstripping many previously reported Li2FeSiO4-based materials. Kinetic analysis reveals a high Li＋ diffusivity due to coupling of the migration of electrons and ions. This research highlights the potential for engineering 3D porous structure to construct highly efficient electrodes for battery applications.

Luminescence properties of a single-host phosphor Ba_(1.8-w)Sr_wLi_(0.4)SiO_4:Ce^(3+),Eu^(2+),Mn^(2+) for WLED

In order to obtain a single-host-white-light phosphor, a series of Bal.8 -x-y-zSrwLi0.4xCexEuyMnzSi04 （BSLS：Ce3＋,Eu2＋, Mn2＋） powder samples were synthesized via high temperature solid-state reaction. The structure and photoluminescence properties were investigated. Under ultraviolet excitation, the emission spectra contained three bands： the 370-470 nm blue band, the 470-570 nm green band and the 570-700 nm red band, which arose from the 5d---4f transitions of Ce3＋ and Eu2＋, and the 4TI---6A1 transition of Mn2＋, respectively. The excitation spectra of the emissions of Ce3＋ and Mn2＋ ions showed the energy transfer from Ce3＋ to Mn2＋. White light emission was obtained from the tri-doped samples of appropriate doping concentration under 31 0-360 nm excitation.