Documents

14_chapter 6.pdf

Description
Description:
Categories
Published
of 18
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Share
Transcript
  181 FABRICATION AND ELECTROCHEMICAL CHARECTARIZATION OF THE CR2032 COIN CELLS USING THE DEVELOPED PURE AND CARBON COATED LiMPO 4  (M= Mn, Co & Ni) NANOPARTICLES CHAPTER – VI  182 CHAPTER - VI FABRICATION AND ELECTROCHEMICAL CHARACTERIZATION OF THE CR2032 COIN CELLS USING THE DEVELOPED PURE AND CARBON COATED LiMPO 4  (M= Mn, Co & Ni) NANOPARTICLES   6.1 General introduction 6.2 Fabrication of CR2032 coin cells 6.3 Electrochemical characterization 6.3.1 LiMnPO 4 /Li and carbon coated LiMnPO 4 / Li cells 6.3.2 LiCoPO 4 /Li and carbon coated LiCoPO 4 / Li cells 6.3.3 LiNiPO 4 /Li and carbon coated LiNiPO 4 / Li cells 6.4 Conclusions References    183 6.1 General Introduction The international electrotechemical commission (IEC) is developing standards for the designation, marking, electrical testing, and safety testing of Li-ion cells and batteries. A  proposed designation and marking system for Li-ion cells utilize five figures in the case of cylindrical cells and six figures in the case of prismatic cells. For example, the common round cell that uses the C/LiCoO 2  cell chemistry is designated ICR2032. The first letter “I” designates an intercalation negative electrode. The second letter designates the type of positive electrode employed, such as C for a cobalt type, N for Nickel type, M for Manganese type or V for a Vanadium type, etc... The third letter will designate the shape of the cell, R for round. The next two figures will designate the diameter in millimeters and then the next three figures the height of the cell, in tenths of millimeters, as they are 20 mm in diameter and 3.2 mm in height. Battery researchers will use to call ICR2032 cell as CR2032. In this chapter, The CR2032 coin cells were assembled with a metallic Li anode to evaluate the pure and carbon coated LiMPO 4  (M=Mn, Co & Ni) and evaluate their electrochemical properties. There are two types of processes to evaluate the electrochemical properties of material. The first is rate capability test  , here the cell is charged at slow rate with a constant voltage and then the fully charged cell is discharged at various current rates to measure the capacity obtained from each discharge rate. Another one is capacity retention test  , in this method; the cell is charged at specific rate and is discharged at the same rate and measure how long the cell sustains the initial capacity without significant degradation of the capacity. The effect of carbon coating  184 over LiMPO 4  (M= Mn, Co & Ni) on the electrochemical properties of carbon coated LiMPO 4 / Li batteries have been investigated and presented in this chapter. 6.2 Fabrication of CR2032 coin cells The cathode materials are coated on aluminum foil and metallic lithium is used as anode. The aluminum foil acts as a current collector for conducting the current in and out of the cell. Both of cathode and anode materials are delivered to the factory in the form of black  powder and to the untrained eye and these are almost indistinguishable from each other. Since contamination between the anode and cathode materials will ruin the battery, great care must be taken to prevent these materials from coming into contact with each other. For this reason, the anodes and cathodes are usually processed in different rooms. The flowchart for the general electrode processing is shown in figure 6.1. The electrochemical performance of CR2032 coin-type cells made up of pure and carbon coated LiMPO 4  (M= Mn, Co & Ni) nanoparticles were evaluated. The cathodes were  prepared by the following process. First, the synthesized samples of pure and carbon coated LiMPO 4  (M= Mn, Co & Ni) were ground to slurry with carbon black (C65, Timcal cooperation, USA) and PVDF (Polyvinylidene fluoride; Sigma Aldrich) binder in  N-Methyl-2-pyrrolidone (NMP) solvent. The formulation of electrode was 80 (active material): 15(carbon black): 5(binder) in weight percentage. Cathodes were prepared by coating of cathode materials slurries on aluminum foil and then dried at 80 o C for 5 h under vacuum. Lithium metal (Sigma Aldrich) was used as an anode, and a micro porous  plastic film (Cellgard 2400, Cellgard Co., USA) was used as separator and the electrolyte solution used comprised of 1.5 M LiPF 6  in a 1:1:1 mixture of ethylene carbonate (EC),
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks
SAVE OUR EARTH

We need your sign to support Project to invent "SMART AND CONTROLLABLE REFLECTIVE BALLOONS" to cover the Sun and Save Our Earth.

More details...

Sign Now!

We are very appreciated for your Prompt Action!

x