Polyphosphonates as ionic conducting polymers. Issue 2 (19th December 2020)

• Record Type: Journal Article
• Authors: Totsch, Timothy R.; Popov, Ivan; Stanford, Victoria L.; Lucius, Aaron L.; Foulger, Stephen H.; Gray, Gary M.
• Is Part Of: Journal of polymer science. Volume 59:Issue 2(2021)
• Page Start: 139
• Page End: 145
• Publication Date: 2020-12-19
• Subjects: 31P{1H} NMR -- cooperative binding -- ionic conductivity -- polymer electrolyte -- polyphosphonate; Polymers -- Periodicals; Polymerization -- Periodicals; Polymerization; Polymers; Periodicals; 547.7
• DOI: 10.1002/pol.20200561
• Languages: English
• ISSNs: 2642-4150

Abstract

Abstract: Polyphosphonates, a class of polymers with the generic formula –[P(R)(X)–OR'O]n –, exhibit a high degree of modularity due to the range of R, R', and X groups that can be incorporated. As such, these polymers may be designed with a polyethylene oxide (PEO) backbone (R' group) and employed as solid polymer electrolytes (SPEs). Two PEO‐containing polyphosphonate analogs (R = Ph; X = S or Se) were doped with LiPF6 and their conductivities were measured. Conductivities were similar (X = S) to or exceeding (X = Se) those of standard PEO systems (just below 10 −4 S/cm at 100°C). Binding models for Li + were generated using 31 P{ 1 H}NMR titration experiments. Binding of Li + by these polyphosphonates followed a positive cooperativity model, and varying the X group (S or Se) affected the observed cooperativity (Hill coefficient = 1.73 and 4.16, respectively). The presence of Se also leads to an increase in conductivity as temperature is raised above the Tg, which is likely an effect of reduced Columbic interactions. Because of their modularity and ease with which cation binding can be evaluated using 31 P{ 1 H} NMR titration experiments, polyphosphonates offer a unique approach for the modification of Li + ion battery technology. Abstract : Polyethylene oxide (PEO)‐based polyphosphonates exhibit promising electrolyte functionality and can provide new insight into polymer‐ion interaction through 31 P{ 1 H} NMR. Polyphosphonates represent a class of phosphorus polymers that are highly modular in their design and functionality. Small changes in their unique structures have shown significant changes to their interaction with ions. Differentiation of phosphorus adducts (from S to Se) has shown an increase in Li + conductivity, as well as a shift in binding behavior.