Glass-Ceramics with High Strength and High Transmittance Obtained by Multi-Factor Controlling

The presence of Li_(2)Si_(2)O_(5) and LiAlSi_(4)O_(10) could effectively improve the elastic modulus and transmittance of lithium disilicate(LD)glass-ceramics.Through synergistically modulation of the crystal content and grain size,we obtained high strength and high transmittance of LD glass-ceramics.The optimal sample had a high transmittance of 90.3%,the hardness was 7.72 GPa,the fracture toughness was 1.07 MPa·m^(1/2),and the elastic modulus was 103.1 GPa.

The Crystallization and Fracture Toughness of Transparent Glass-ceramics with Various Al_(2)O_(3) Additions for Mobile Devices

Li_(2)O-Al_(2)O_(3)-SiO_(2)(LAS)glass-ceramics were prepared by a melting method.Effects of different Al_(2)O_(3)content on the structure,crystallization,transmittance and fracture toughness of LAS glassceramics were investigated by means of XRD,FESEM and other methods as well.The results showed that the glass transition temperature and crystallization temperature of samples increased as the content of Al_(2)O_(3)increased from 4.1 wt%to 13.1 wt%,which restrained the precipitation of lithium disilicate crystals.The main crystalline phase of glass-ceramics transformed from lithium disilicate and petalite to silicon dioxide,which reduced the fracture toughness of glass-ceramics.When the Al_(2)O_(3)content was 7.1 wt%,the specimen had outstanding transmittance and fracture toughness.The transmittance was 90.32%.The fracture toughness was 1.13 MPa•m^(1/2).Compared with high-alumina glass,the fracture toughness of the glass-ceramic was greatly improved,and it could be used as a new type of protective material for mobile devices.

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.

Crystallization and Microstructure of Li_2O-Al_2O_3-SiO_2 Glass-ceramics Produced with Environmentally Acceptable Fining Agents

Lithium aluminosilicate(LAS) glass-ceramics with a few gas bubbles were prepared when SnO2, V2O5 and CeO2 were used as fining agents. The effect of the complex fining agent on the crystallization, phase compositions and microstructure of LAS glass–ceramics was investigated by differential thermal analysis, X-ray diffraction and scanning electron microscopy, respectively. The results show that the introduction of fining agents promotes the crystallization at a lower temperature and has little effect on the compositions of main crystalline phase and microstructure when the crystalline phase remains β-quartz. The special colors of LAS glass-ceramics can be obtained by controlling the crystallization temperature and the amounts of V2O5 and CeO2. The complex fining agent is an environmentally friendly alternative to toxic As2O3 and can be also used as a colorant for colored LAS glass-ceramics.

Air-stable Li_(3.12)P_(0.94)Bi_(0.06)S_(3.91)I_(0.18)solid-state electrolyte with high ionic conductivity and lithium anode compatibility toward high-performance all-solid-state lithium metal batteries

Sulfide solid-state electrolytes(SSEs)with superior ionic conductivity and processability are highly promising candidates for constructing all-solid-state lithium metal batteries(ASSLMBs).However,their practical applications are limited by their intrinsic air instability and serious interfacial incompatibility.Herein,a novel glass-ceramic electrolyte Li_(3.12)P_(0.94)Bi_(0.06)S_(3.91)I_(0.18)was synthesized by co-doping Li_(3)PS_(4)with Bi and I for high-performance ASSLMBs.Owing to the strong Bi-S bonds that are thermodynamically stable to water,increased unit cell volume and Li+concentration caused by P5+substitution with Bi3+,and the in situ formed robust solid electrolyte interphase layer LiI at lithium surface,the as-prepared Li_(3.12)P_(0.94)Bi_(0.06)S_(3.91)I_(0.18)SSE achieved excellent air stability with a H2S concentration of only 0.205 cm^(3)g^(-1)(after 300 min of air exposure),outperform-ing Li_(3)PS_(4)(0.632 cm^(3)g^(-1))and the most reported sulfide SSEs,together with high ionic conductivity of 4.05 mS cm^(-1).Furthermore,the Li_(3.12)P_(0.94)Bi_(0.06)S_(3.91)I_(0.18)effectively improved lithium metal stability.With this SSE,an ultralong cyclabil-ity of 700 h at 0.1 mA cm^(-2)was realized in a lithium symmetrical cell.Moreover,the Li_(3.12)P_(0.94)Bi_(0.06)S_(3.91)I_(0.18)-based ASSLMBs with LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)cathode achieved ultrastable capacity retention rate of 95.8%after 300 cycles at 0.1 C.This work provides reliable strategy for designing advanced sulfide SSEs for commercial applications in ASSLMBs.