Screening and Analysis of Carbon additives used to improve DCA of Lead Acid Batteries
Mentor 1
Benjamin Church
Location
Union Wisconsin Room
Start Date
29-4-2016 1:30 PM
End Date
29-4-2016 3:30 PM
Description
Lead Acid battery technology today is used throughout the automotive industry for SLI applications. Many seek to expand the use of this type of battery to include start-stop and regenerative braking applications. This application is currently hindered due to the lead acid battery’s inability to supply and accept high rate charges without long term performance degradation. The application of high rates of supplying and accepting charges is referred to as Dynamic Charge Acceptance (DCA). To improve upon the long term effects of caused by DCA, carbon additives can be added to the electrode mass to promote the formation of a porous structure and maintain a high surface area through charging and discharging cycles. While the addition of carbon additives improve DCA, it also acts as a catalyst for the formation of H2. If gone unchecked, the formation of H2 can lead to a change of the internal chemistry of the battery, hindering performance. For carbon additive to the electrode-mass to be beneficial for the cell, water loss due to overpotential electrolysis has to be reduced by 50% at 2.45V and 60 oC. A quick screening process has been devised to test several different commercially available carbon additives that could be potential candidates for the DCA improvement. This process involves the use of microelectrodes in an acid solution to undergoing a cyclic voltammetry test which produces graphs from which the production of hydrogen gas can be determined through analysis of slopes and the derivation of the hydrogen evolution point. Results of this research will be used to determine which carbon additives would most likely meet requirements of battery cells in later stages of the DCA project.
Screening and Analysis of Carbon additives used to improve DCA of Lead Acid Batteries
Union Wisconsin Room
Lead Acid battery technology today is used throughout the automotive industry for SLI applications. Many seek to expand the use of this type of battery to include start-stop and regenerative braking applications. This application is currently hindered due to the lead acid battery’s inability to supply and accept high rate charges without long term performance degradation. The application of high rates of supplying and accepting charges is referred to as Dynamic Charge Acceptance (DCA). To improve upon the long term effects of caused by DCA, carbon additives can be added to the electrode mass to promote the formation of a porous structure and maintain a high surface area through charging and discharging cycles. While the addition of carbon additives improve DCA, it also acts as a catalyst for the formation of H2. If gone unchecked, the formation of H2 can lead to a change of the internal chemistry of the battery, hindering performance. For carbon additive to the electrode-mass to be beneficial for the cell, water loss due to overpotential electrolysis has to be reduced by 50% at 2.45V and 60 oC. A quick screening process has been devised to test several different commercially available carbon additives that could be potential candidates for the DCA improvement. This process involves the use of microelectrodes in an acid solution to undergoing a cyclic voltammetry test which produces graphs from which the production of hydrogen gas can be determined through analysis of slopes and the derivation of the hydrogen evolution point. Results of this research will be used to determine which carbon additives would most likely meet requirements of battery cells in later stages of the DCA project.
