Multi-Porous Carbon Materials Modified By Pb And Ba

In order to exploit the advantages of lead-acid batteries and supercapacitors at the same time, ultra-batteries are brought forward. But the negative plate of carbon evolves hydrogen gas more distinctly at the end of charging and its working potential is not similar to that of the lead-acid negative plate. In order to solve these problems, the following methods are proposed.First, the powder of Pb, the powder of Pb and BaSO4 are doped into the activated carbon plate respectively by mechanical mixing. The results of Cyclic Voltammetry, Chronoamperometry and constant current charge-discharge tests indicate that, the carbon plate has a more negative potential of hydrogen gassing, a more negative working potential and a higher capacity after it is doped with Pb. With the increasement of the concentration of the Pb, the influence is stronger. Therefore, it is the best when the plate is doped with Pb of 9%. It has a nearly constant potential of hydrogen evolution, distinctly lower hydrogen gassing rate after the plate containing Pb of 9% is doped with BaSO4, and it can restrain the sulphation of Pb effectively. With the increasement of the concentration of BaSO4, the plate has a nearly contant potential of hydrogen evolution and a lower hydrogen gassing rate. Therefore, the Pb of 9% and BaSO4 of 9% doped into the carbon is the best.Then the powder of Pb, the powder of Pb and BaSO4 are doped into the activated carbon plate respectively by depositon. The result indicates that the carbon plate has a more negative potential of hydrogen gassing, a lower hydrogen gassing rate, a more negative working potential and a higher capacity after it is doped with Pb. In the deposition, the plate made from the solution of Pb(NO3)2 with a concentration of 0.4 mol/L has the best properties. It has a more positive potential of hydrogen evolution and a lower hydrogen gassing rate after the plate is doped with BaSO4. With the increasement of the concentration of BaSO4, the plate has nearly contant potential of hydrogen evolution and hydrogen gassing rate. The electrodes made from the solutions of Pb(NO3)2 of 0.4mol/L and Ba(CH3COO)2 of 0.036 mol/L are considered as the best .The two methods of doping are compared in the end. It is considered that the plate prepared by deposition can make its potential of hydrogen gassing more negative effectively. The methods of mechanical mixing and deposition have their own advantages with regard to hydrogen gassing rate.