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Sodium metal batteries (SMBs) are cost-effective and environmentally sustainable alternative to lithium batteries. However, at present, limitations such as poor compatibility, low coulombic efficiency (CE), and high electrolyte cost hinder their widespread application. Herein, we propose a non-flammable, low-concentration electrolyte composed of 0.3 M NaPF₆in propylene carbonate (PC), fluoroethylene carbonate (FEC), and 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE). This low-concentration electrolyte not only reduces cost but also delivers rapid ion diffusion and superior wetting properties. While the Na||FePO₄system with this electrolyte demonstrates slightly reduced performance at room temperature compared to standard-concentration formulations (S-PFT), it excels at both high (55 °C) and low (−20 °C) temperatures, showcasing its balanced performance. At 0.5 C (charge)/1 C (discharge), capacity retention reaches 92.8% at room temperature and 98.5% at elevated temperature, with CE values surpassing 99% and 99.63%, respectively, and significant performance sustained at −20 °C at 0.2 C. This electrolyte development thus offers a well-rounded, economically viable path to high-performance SMBs for diverse environmental applications.