Using QPAC® Polyalkylene Carbonate as a solid state electrolyte for flexible solid lithium batteries
Work has been done by numerous research organizations to investigate the use of QPAC®25 polyethylene carbonate (PEC) and QPAC®40 polypropylene carbonate (PPC) in solid lithium ion battery applications. Research has been ongoing for many years to find an alternative to liquid electrolyte batteries because of their inherent safety issues mainly due to the volatility and combustion of the liquid carbonate organic electrolyte. Solid polymer electrolytes can also offer enhanced flexibility and process ability. The challenge with the past solid polymer electrolyte has been low ionic conductivity. There has been a lot of work to overcome this past issue so that the solid lithium batteries perform as well as the liquid polymer batteries.
QPAC®25 polyethylene carbonate and QPAC®40 polypropylene carbonate are both being investigated as polymer candidates for electrolytes. Carbonate based solvents are usually used as the electrolyte solution in Li-ion batteries because of their high dielectric constant. Therefore the carbonate groups of QPAC®25 and QPAC®40 provides a good structure for the polymer framework. The work shows that the PEC can form a high performing polymer matrix for the electrolyte and shows very good ion conductive properties. Additional work by other groups focused on PPC for the polymer matrix. This work also showed favorable battery performance results.
Overall, the use of both QPAC®25 polyethylene carbonate and QPAC®40 polypropylene carbonate exhibited high conductivity and high ionic transference number along with good mechanical strength. The results show comparable performance to liquid electrolyte battery technology. Therefore, the safety issues and flexibility constraints of liquid polymer batteries can be eliminated without sacrificing performance by using these polyalkylene carbonate polymers in the electrolyte formulation.