Lithium metal and anode-free batteries are generating significant interest due to their remarkably high energy density in a compact size, paving the way for extended range in electric vehicles. However, the high-voltage cathode and reactive lithium metal anode tend to catalyze the decomposition of conventional carbonate and ether-based electrolytes, leading to significant gassing, swelling, and rapid capacity fade. Additionally, these electrolytes contain one or more highly flammable components, reducing the overall safety by acting like a fuel during a thermal event. Here, we highlight the use of a non-flammable localized high-concentration electrolyte based on Triethyl Phosphate in a Copper (Cu) || LiNi0.8Mn0.1Co0.1O2 (NMC811) stacked pouch cell. This proposed electrolyte combination significantly reduces gassing, maintains non-flammability, and does not compromise on cycle life.