Improving the Performance of Lead-Acid Batteries Through GUITAR Coated Additives
Additional Funding Sources
The project described was supported by a student grant from the UI Office of Undergraduate Research.
Abstract
University of Idaho research has shown that ceramic fibers coated with GUITAR (Graphite from the University of Idaho Thermolyzed Asphalt Reaction, patent-pending) can improve lead-acid battery performance by increasing the conductivity within the positive plate. It is postulated that by converting the hydrophobic GUITAR surface characteristic to be more hydrophilic, lead-acid battery performance will be further improved. A hydrophilic GUITAR surface should provide a better bond and improved conductivity within the positive active material (PAM) of the cell.
Previous experimentation determined that heated-air treatments make the GUITAR coated ceramic fibers hydrophilic by partially oxidizing the surface. Said treatments were conducted by heating GUITAR coated ceramic fibers at 330 °C with 20 SCFH of compressed air flow for 1 hour. Other treatments including soaking the GUITAR coated fibers in methanol were also utilized to create a hydrophilic surface. After each treatment, the conductivity and hydrophobicity of the fibers was evaluated and compared to GUITAR coated fibers prior to treatment. Precursory results highlight that heat-air treatments of GUITAR coated fibers both increase the hydrophilic surface properties while maintaining the conductivity of the coating. For instance, the average conductivity of the heated-air treated samples was between 40-60 Siemens per meter while the average conductivity of ceramic fibers coated once in GUITAR was below 40 Siemens per meter. Results regarding the methanol soak appeared less conclusive, with limited effects on the surface of the GUITAR.
Partially hydrophilic GUITAR coated fibers and hydrophobic GUITAR coated fibers were then hand pasted with lead (II) oxide onto positive lead grids. These plates were then tested on a battery testing apparatus and compared to standard plates and plates with various treated and untreated additives. As a whole, the performance of the cells was analyzed through the max utilization percentages, which is the maximum percentage of the positive active material utilized during a discharge. It is significant to note that this experimentation consisted of 100% depth discharge and a 20-hour cycling preset sequence. Preliminary results indicate that hydrophilic GUITAR coated fibers improve the performance of lead-acid cells. For example, plates containing heated-air treated GUITAR coated fibers had an average max utilization of 59.46% while plates with untreated GUITAR coated fibers reached 54.89% max utilization. Additionally, positive plates containing GUITAR coated fibers also have improved structural integrity when contrasted against plates containing no additives. These preliminary results indicate that hydrophilic, GUITAR coated additives have the potential to increase both the efficiency and life of lead-acid batteries.
Improving the Performance of Lead-Acid Batteries Through GUITAR Coated Additives
University of Idaho research has shown that ceramic fibers coated with GUITAR (Graphite from the University of Idaho Thermolyzed Asphalt Reaction, patent-pending) can improve lead-acid battery performance by increasing the conductivity within the positive plate. It is postulated that by converting the hydrophobic GUITAR surface characteristic to be more hydrophilic, lead-acid battery performance will be further improved. A hydrophilic GUITAR surface should provide a better bond and improved conductivity within the positive active material (PAM) of the cell.
Previous experimentation determined that heated-air treatments make the GUITAR coated ceramic fibers hydrophilic by partially oxidizing the surface. Said treatments were conducted by heating GUITAR coated ceramic fibers at 330 °C with 20 SCFH of compressed air flow for 1 hour. Other treatments including soaking the GUITAR coated fibers in methanol were also utilized to create a hydrophilic surface. After each treatment, the conductivity and hydrophobicity of the fibers was evaluated and compared to GUITAR coated fibers prior to treatment. Precursory results highlight that heat-air treatments of GUITAR coated fibers both increase the hydrophilic surface properties while maintaining the conductivity of the coating. For instance, the average conductivity of the heated-air treated samples was between 40-60 Siemens per meter while the average conductivity of ceramic fibers coated once in GUITAR was below 40 Siemens per meter. Results regarding the methanol soak appeared less conclusive, with limited effects on the surface of the GUITAR.
Partially hydrophilic GUITAR coated fibers and hydrophobic GUITAR coated fibers were then hand pasted with lead (II) oxide onto positive lead grids. These plates were then tested on a battery testing apparatus and compared to standard plates and plates with various treated and untreated additives. As a whole, the performance of the cells was analyzed through the max utilization percentages, which is the maximum percentage of the positive active material utilized during a discharge. It is significant to note that this experimentation consisted of 100% depth discharge and a 20-hour cycling preset sequence. Preliminary results indicate that hydrophilic GUITAR coated fibers improve the performance of lead-acid cells. For example, plates containing heated-air treated GUITAR coated fibers had an average max utilization of 59.46% while plates with untreated GUITAR coated fibers reached 54.89% max utilization. Additionally, positive plates containing GUITAR coated fibers also have improved structural integrity when contrasted against plates containing no additives. These preliminary results indicate that hydrophilic, GUITAR coated additives have the potential to increase both the efficiency and life of lead-acid batteries.