New material for use in solid-state batteries combines copper with cellulose nanofibrils—polymer tubes derived from wood

https://www.brown.edu/news/2021-10-21/ionconductor

"could be used as either a solid electrolyte or as an ion-conducting binder for the cathode... The paper-thin material has an ion conductivity that is 10 to 100 times better than other polymer ion conductors [such as those made of] ceramic materials, which are great at conducting ions but they're also thick, rigid and brittle [allowing] Stresses during manufacturing as well as [during] charging and discharging [which] can lead to cracks and breaks"