scholarly journals Role of precursor chemistry in the direct fluorination to form titanium based conversion anodes for lithium ion batteries

RSC Advances ◽  
2015 ◽  
Vol 5 (108) ◽  
pp. 88876-88885 ◽  
Author(s):  
Jonathan M. Powell ◽  
Jamie Adcock ◽  
Sheng Dai ◽  
Gabriel M. Veith ◽  
Craig A. Bridges

An effective approach to increasing the reversible specific capacity of TiOF2 conversion electrodes is presented. The capacity increased greatly when the precursor was partially reduced before direct fluorination in a fluidized bed reactor.

Nanoscale ◽  
2014 ◽  
Vol 6 (24) ◽  
pp. 15020-15028 ◽  
Author(s):  
Yun Guang Zhu ◽  
Ye Wang ◽  
Zhao Jun Han ◽  
Yumeng Shi ◽  
Jen It Wong ◽  
...  

The catalytic role of Ge promotes the reversible electrochemical reaction of SnO2 to Sn, overcoming the limitation of the traditional specific capacity of SnO2.


Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Yiqiu Xiang ◽  
Ling Xin ◽  
Jiwei Hu ◽  
Caifang Li ◽  
Jimei Qi ◽  
...  

Extensive use of fossil fuels can lead to energy depletion and serious environmental pollution. Therefore, it is necessary to solve these problems by developing clean energy. Graphene materials own the advantages of high electrocatalytic activity, high conductivity, excellent mechanical strength, strong flexibility, large specific surface area and light weight, thus giving the potential to store electric charge, ions or hydrogen. Graphene-based nanocomposites have become new research hotspots in the field of energy storage and conversion, such as in fuel cells, lithium-ion batteries, solar cells and thermoelectric conversion. Graphene as a catalyst carrier of hydrogen fuel cells has been further modified to obtain higher and more uniform metal dispersion, hence improving the electrocatalyst activity. Moreover, it can complement the network of electroactive materials to buffer the change of electrode volume and prevent the breakage and aggregation of electrode materials, and graphene oxide is also used as a cheap and sustainable proton exchange membrane. In lithium-ion batteries, substituting heteroatoms for carbon atoms in graphene composite electrodes can produce defects on the graphitized surface which have a good reversible specific capacity and increased energy and power densities. In solar cells, the performance of the interface and junction is enhanced by using a few layers of graphene-based composites and more electron-hole pairs are collected; therefore, the conversion efficiency is increased. Graphene has a high Seebeck coefficient, and therefore, it is a potential thermoelectric material. In this paper, we review the latest progress in the synthesis, characterization, evaluation and properties of graphene-based composites and their practical applications in fuel cells, lithium-ion batteries, solar cells and thermoelectric conversion.


2009 ◽  
Vol 289-292 ◽  
pp. 293-300
Author(s):  
L. Sánchez ◽  
F.J. Bolívar ◽  
M.P. Hierro ◽  
F.J. Pérez

In this work, iron aluminide coatings were developed by Chemical Vapor Deposition in Fluidized Bed Reactor (CVD-FBR) on ferritic-martensitic steels. Small additions of zirconium powder were introduced in the fluidized bed; as a consequence, the obtained coatings are thicker than that without zirconium additions. When Zr powders are added in the fluidized bed, the deposition atmosphere drastically changes, leading to increase the deposition rate. Thermodynamic calculations were carried out to simulate the modifications in the CVD atmosphere in the Al/Zr deposition system in comparison to the single aluminization. In order to optimize the conditions of the deposition, parameters such as temperature and concentration of zirconium introduced into the bed were evaluated and compared with the results obtained for the single aluminum deposition.


2021 ◽  
Vol 10 (1) ◽  
pp. 210-220
Author(s):  
Fangfang Wang ◽  
Ruoyu Hong ◽  
Xuesong Lu ◽  
Huiyong Liu ◽  
Yuan Zhu ◽  
...  

Abstract The high-nickel cathode material of LiNi0.8Co0.15Al0.05O2 (LNCA) has a prospective application for lithium-ion batteries due to the high capacity and low cost. However, the side reaction between the electrolyte and the electrode seriously affects the cycling stability of lithium-ion batteries. In this work, Ni2+ preoxidation and the optimization of calcination temperature were carried out to reduce the cation mixing of LNCA, and solid-phase Al-doping improved the uniformity of element distribution and the orderliness of the layered structure. In addition, the surface of LNCA was homogeneously modified with ZnO coating by a facile wet-chemical route. Compared to the pristine LNCA, the optimized ZnO-coated LNCA showed excellent electrochemical performance with the first discharge-specific capacity of 187.5 mA h g−1, and the capacity retention of 91.3% at 0.2C after 100 cycles. The experiment demonstrated that the improved electrochemical performance of ZnO-coated LNCA is assigned to the surface coating of ZnO which protects LNCA from being corroded by the electrolyte during cycling.


Ionics ◽  
2020 ◽  
Vol 27 (1) ◽  
pp. 65-74
Author(s):  
Jinhuan Yao ◽  
Yanwei Li ◽  
Renshu Huang ◽  
Jiqiong Jiang ◽  
Shunhua Xiao ◽  
...  

2016 ◽  
Vol 18 (6) ◽  
pp. 4721-4727 ◽  
Author(s):  
Bo Lu ◽  
Yicheng Song ◽  
Qinglin Zhang ◽  
Jie Pan ◽  
Yang-Tse Cheng ◽  
...  

The crucial role of mechanical stress in voltage hysteresis of lithium ion batteries in charge–discharge cycles is investigated theoretically and experimentally.


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