Gamma titanium phosphate as an electrode material for Li-ion and Na-ion storage: performance and mechanism

2016 ◽  
Vol 4 (46) ◽  
pp. 18084-18090 ◽  
Author(s):  
Xinghua Xiang ◽  
Xiaocheng Li ◽  
Kongyao Chen ◽  
Yang Tang ◽  
Min Wan ◽  
...  

Layered G-TiP can store Li+ and Na+ ions via a local ion exchange process and redox reaction. Despite the large radius of Na+, G-TiP exhibits a higher structural tolerance upon (de)sodiation and a better capacity retention at low voltage.

2002 ◽  
Vol 756 ◽  
Author(s):  
Seiichi Suda ◽  
Hiroyuki Ishii ◽  
Kiyoshi Kanamura

ABSTRACTLithium ionic conductor, (La, Li)TiO3, has synthesized with La/Li-TiO2 amorphous spheres that were obtained by sol-gel and ion-exchange method, and succeeding La3+/Li+ partial ion exchange. In this work, La /Li ion exchange conditions were mainly investigated in order to obtain dense (La, Li)TiO3 ceramics that have highly ionic conductivities. La +/Li+ ion exchange behavior was changed with ion-exchange solutions, and the Li/Ti ratio was increased with an increase in ethanol/water ratio in the solvent used for La3+/Li+ partial ion exchange. The use of an adequate ethanol/water ratio resulted in La/Li-TiO2 amorphous spheres with the composition of La/Li/Ti=0.54/0.34/1.00, and sintering of the spheres at 1200°C for 5 h in air led to dense (La, Li)TiO3 ceramics which exhibit the conductivity of 4.0 × 10-3 S cm-1 at 25°C.


2001 ◽  
Vol 16 (6) ◽  
pp. 1554-1558 ◽  
Author(s):  
F. Caccavale ◽  
C. Sada ◽  
F. Segato ◽  
L. D. Bogomolova ◽  
V. A. Jachkin ◽  
...  

Copper-doped LiNbO3 layers prepared by an Cu–Li ion-exchange process are characterized by electronic paramagnetic resonance. It is found that the majority of Cu2+ ions are coupled by strong exchange interactions which is characteristic of short distances between paramagnetic ions. Such ions are accumulated in a thin layer near the crystal surface and can enter in new crystalline phases formed as a result of the Cu–Li ion exchange. A small amount of Cu2+ ions is incorporated into weakly distorted LiNbO3 crystal lattice inside the diffusion layer.


2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.


2014 ◽  
Vol 6 (19) ◽  
pp. 17236-17244 ◽  
Author(s):  
Xiaoting Zhang ◽  
Jisheng Zhou ◽  
Huaihe Song ◽  
Xiaohong Chen ◽  
Yu. V. Fedoseeva ◽  
...  

1986 ◽  
Vol 20 (9) ◽  
pp. 1177-1184 ◽  
Author(s):  
Arup K. Sengupta ◽  
Dennis Clifford ◽  
Suresh Subramonian

1985 ◽  
Vol 60 ◽  
Author(s):  
J. D. Barrie ◽  
D. L. Yang ◽  
B. Dunn ◽  
O. M. Stafsudd

AbstractIon exchanged ß“-aluminas display a number of interesting optical properties which suggest that the material is well suited for application as a solid state laser host. Small platelets of Nd3+ Ion exchanged β“-alumina exhibit laser action with gain coefficients many times greater than YAG. The versatility of the ion exchange process enables one to form a wide variety of compounds with different active ions and concentrations, thereby allowing the study of many different effects within a single host crystal.


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