Phenomenology of Lithium Dendrite Suppression in Solid Electrolytes Through the Inclusion of Ferroelectric Materials

Li dendrite penetrates solid electrolyte (SE) beyond a certain critical current density (CCD) in Li metal-based SSBs, resulting in electrical shorting issue, especially under fast charging conditions. This has strongly limited the ability to develop viable fast-charging, high-energy-density solid state batteries (SSBs).<br/><br/>Multiple strategies have been reported to mitigate dendrite formation in SSBs. These have included engineering the dielectric properties of the SE to control transport and interface reactions. While the results indicate a direct impact of polarization on performance, reported results have not yet demonstrated critical current densities and lifetime improvements sufficient to invoke commercial interest.<br/><br/>In the light of this we set out to develop a composite PVDF-based SE system to utilize in conjunction with a Li metal anode that could mitigate dendrite formation and achieve high current densities and cycle life. Our innovation has resulted in a remarkable increase in the CCD to the extent that our cells ceased operation due to reaching the upper voltage limit of the battery tester, rather than encountering electrical shorting issues. At the end, we speculate upon the mechanisms, which can be due to a coupled piezoelectricity, mechanics, and electrochemistry effects.