Development of innovative polymer electrolytes that simultaneously possesses high mechanical stiffness as well as liquid-like ion motions is desirable for safer lithium-ion secondary batteries. Herein, bifunctional poly(ethylene glycol) diacrylate (PEGDA) based cross-linked network polymer electrolytes (PE) plasticized by tetraglyme at various lithium salt concentrations were fabricated via a solvent-free UV-curing process using a photo-initiator, 2,2-dimethoxy-2-phenylacetophenone (DMAP). The outstanding results demonstrate potential for safer high-performance rechargeable lithium-ion batteries.