It has long been recognized that secondary batteries containing lithium metal anodes have some of the highest theoretical energy densities of known battery chemistries, due to the light weight and low deposition potential of lithium metal. Lithium metal batteries have several roadblocks to effective, wide-spread implementation: lithium metal is reactive with many lithium-ion electrolytes causing low coulombic efficiency and it electrodeposits unevenly upon recharge, creating a safety hazard due to potential short-circuit. Polymer electrolytes have been under investigation for several years due to their relatively low reactivity with lithium metal and potential to electrodeposit more uniformly, due to their higher mechanical strength. This dissertation researches polymer-ceramic hybrid electrolytes with several goals: improving room temperature ionic conductivity of the electrolytes while maintaining chemical stability and mechanical integrity, allowing tunability of mechanical properties, improving lithium-ion transference number of the electrolyte, and studying the lithium metal dendrite growth as a function of electrolyte properties. It is found that constraint of the polymer chain by tethering to a nanoparticle improves ambient temperature ionic conductivity by mitigating matrix crystallization. Immobilization of anionic ligands onto the nanoparticle is found to be a facile way to synthesize nanometric lithium salts with improved transference numbers; importantly, the chemistry of the suspending solvent is found to have a significant impact on ionic conductivity. It is found that polyether-based electrolytes with and without hybrid nanoparticle fillers exhibit the same lithium metal battery lifetime regardless of mechanical properties or ionic conductivity. Surprisingly, certain copolymer electrolytes are found to provide for exceeding longer lifetimes.