Carbon nanotube-metal nanocomposites as flexible, free standing, binder free high performance anode for Li-ion battery
The present invention relates to carbon nanotubes-metal nano composite by chemical route and the corresponding development of strong and flexible, light weight, self-supporting anode through simple vacuum filtration technique, which is favored by the high aspect ratio of the Multi-walled carbon nanotubes. The self-supported anode has an added advantage that it can be used as electrodes without binder and electrical conductor (unlike other carbonaceous powder materials) that helps us to elucidate the precise electrochemical properties. The metals used can be Sn, Si, Al, etc. The developed high capacity, free-standing anode can be used in rechargeable Li-ion batteries and is demonstrated successfully in powering solar lantern.
1. A process for the preparation of flexible, free standing, anode material in the form of paper,
wherein the paper comprises Carbon Nano Tubes (CNT) and metal in the ratio ranging between 99:1 to 50:50 having specific capacity in the range of 136 to 417 mAh/g after 50 cycles by C/10 rate; and
wherein said process consists of the steps of:
(i) dispersing the carbon nanotubes in a solvent by using ultrasonication for 3 hours;
(ii) dissolving inorganic metallic salts in distilled water by ultrasonication;
(iii) mixing the solution obtained from step (i) and (ii) using magnetic stirrer for 1 hour;
(iv) refluxing of the solution obtained from step (iii) in air at 100° C. for 4 hours;
(v) filtering of solution obtained from step (iv) in a vacuum filtration unit to obtain a metal oxide/carbon nanotube nanocomposite;
(vi) washing of filtrate obtained in step (v) using Deionized water;
(vii) drying of composite obtained from step (vi) in vacuum oven; and
(viii) obtaining the flexible, free standing, anode material in the form of paper through paper making technology using vacuum filtration.
2. The process as claimed in step (i) of claim 1 , wherein the solvent is selected from the group consisting of derivatives of ethylene glycol and polyols selected from the group consisting of diethylene glycol and polyethylene glycol.
3. The process as claimed in step (i) of claim 1 , wherein the carbon nanotubes are selected from the group consisting of multi-walled carbon nanotubes (MWCNT), single-walled carbon nanotubes (SWCNTs), and combinations thereof.