Association and Diffusion of Li+ in Carboxymethylcellulose Solutions for Environmentally Friendly Li-ion Batteries

作者：Casalegno Mose; Castiglione Franca; Passarello Marco; Mele Andrea; Passerini Stefano; Raos Guido

来源：Chemsuschem, 2016, 9(14): 1804-1813.

DOI：10.1002/cssc.201600160

• aqueous Li-ion batteries
• diffusion
• md simulations
• natural polyelectrolytes
• NMR spectroscopy

Carboxymethylcellulose (CMC) has been proposed as a polymeric binder for electrodes in environmentally friendly Li-ion batteries. Its physical properties and interaction with Li+ ions in water are interesting not only from the point of view of electrode preparation-processability in water is one of the main reasons for its environmental friendliness-but also for its possible application in aqueous Li-ion batteries. We combine molecular dynamics simulations and variable-time pulsed field gradient spin-echo (PFGSE) NMR spectroscopy to investigate Li+ transport in CMC-based solutions. Both the simulations and experimental results show that, at concentrations at which Li-CMC has a gel-like consistency, the Li+ diffusion coefficient is still very close to that in water. These Li+ ions interact preferentially with the carboxylate groups of CMC, giving rise to a rich variety of coordination patterns. However, the diffusion of Li+ in these systems is essentially unrestricted, with a fast, nanosecond-scale exchange of the ions between CMC and the aqueous environment.

• 出版日期2016-7-21