Study of polypyrrole graphite composite as anode material for secondary lithium-ion batteries

Effects of polypyrrole on the performance of nickel oxide anode materials for rechargeable lithium-ion batteries

“…The diameter of this semicircle gives the charge-transfer resistance (R ct ), which is a measure of the charge-transfer kinetics. 25 We found that the diameter of the semicircle in the medium frequency region for the NiO-PPy composite is smaller than for the NiO cells after 5 and 30 cycles. The reduction in the diameter of the semicircle for the composite could be attributed to a decrease in the interparticle contact resistance.…”

Electrochemical characterization of a polypyrrole/Co0.2CrOx composite as a cathode material for lithium ion batteries

“…1 ) remains stable in the temperature range used in the experiment. It can also be seen from the figure that the composites show weight loss at a temperature of 420 • C, which corresponds to the oxidation of polypyrrole [16]. There is no further weight change in the composites after the initial oxidation of polypyrrole, which shows that the base material remains unaffected after this initial weight loss.…”

“…Thermogravimetric analysis has been used to quantify the amount of polypyrrole in the composite materials [16]. TGA analysis was done in argon filled glove box, with the temperature being scanned from room temperature to 650 • C at a rate of 5 • C/min.…”

Polypyrrole Composites: Electrochemical Synthesis, Characterizations and Applications

“…As S is an insulating material, the cathode material is combined with 30-55% carbon black (Jin et al, 2003;Song et al, 2004) of the total weight of the electrode materials. Recently, PPy has been used as an additive to improve the performance of anode and cathode materials in Li-ion batteries (Guo et al, 2005;Pasquier et al, 1999;Veeraraghavan et al, 2002;Wang et al, 2006). Very recently, Liang et al, (2010) observed that the morphology of the PPy combined with S shows a significant effect on the dispersion status and electrochemical behaviour of S. When S was highly combined with two types of PPy, G-PPy and T-PPy, by in-situ oxidation and co-heating methods, the cycle durability of the composite was more favourable with the TPPy matrix in comparison with G-PPy matrix.…”

“…To ensure long cycle life and safety, the use of graphite, among carbon materials, as anode for the Li-ion battery is favoured, however carbonaceous anodes exhibit capacity loss during the first intercalanation step. To minimize the capacity loss the graphite electrode was coated by a thin PPy film, the later is found to decrease the initial E rev capacity loss of the graphite anode (Veeraraghavan et al, 2002). The decrease in the E rev capacity loss has been ascribed to the reduction in the thickness of the solid electrolyte interface (SEI) layer.…”