Various embodiments relate to a method comprising forming a template forming a template from a template precursor, wherein the template contains an entrapped ceramic precursor, which can be further processed to form a ceramic solid, such as an oxide ceramic solid. In one embodiment, the template precursor is a hydrogel precursor and the template is a hydrogel template. The hydrogel template can include, for example, agarose, chitosan, alginate or a photo-initiating receptive hydrogel template such as a functionalized poly(ethylene glycol). Various devices, including electrolyte interfaces and energy storage devices, as well as thermoelectric devices are also provided. In one embodiment, the oxide ceramic solid is a cubic garnet having a nominal formula of Li.sub.7La.sub.3Zr.sub.2O.sub.12 (LLZO).
STATEMENT OF GOVERNMENT RIGHTS
 This invention was made with government support under grant W911NF-10-2-0089 awarded by the United States Army Research Office and under grant DE-SC0001054 awarded by the United States Department of Energy. The government has certain rights in this invention.