The relationship between ion transport and polymer dynamics is central to the pursuit of solid polymer electrolytes for lithium batteries. This understanding is critical to achieve solid polymer electrolyte systems of sufficiently high ion conductivities. Solid polymer electrolytes are highly attractive from the perspective of their mechanical properties and low flammability compared to current electrolytes, however their ionic conductivities are typically an order of magnitude slower than the liquid electrolytes that are used today in commercial Li+ ion battery systems. Here we introduce inelastic neutron scattering (INS) as a tool to quantify the coupling between the local dynamics in the polymer electrolyte with the ion mobility through this ion transport media. INS technqiues are well suited for this task as they are primarily sensitive to the dynamics of the hydrogen rich polymer electrolyte and not the Li+ ions themselves. This is complimentary to dielectric or electrical impedance measurements which are primarily senstive to the ion dynamics. The combination of INS and dielectric measurements provides the opportunity to directly correlate ion dynamics with the dynamics of the host electrolyte to better understand this complicated ion transport process. In this chapter we briefly introduce some of the basic INS techniques that can be used for these studies and review the current literature focused on understanding the dynamics in organic and polymer electrolytes for Li+ ion batteries.
Citation: for Energy Storage and Delivery: Polyelectrolytes for Batteries and Fuel Cells
Publisher Info: American Chemical Society, Washington DC, NW, DC
Pub Type: Book Chapters
battery, lithium ion, ion transport, inelastic neutron scattering, polymer dynamics, energy storage