Lithium Thionyl Chloride (Li-SOCl2)
Battery Chemistries · 9 specs
Direct Answer
Lithium Thionyl Chloride (Li-SOCl2) is an ultra-high-density industrial primary chemistry delivering 3.6V nominal per cell. With gravimetric energy density reaching 650–700 Wh/kg, exceptional temperature tolerance (-60°C to +85°C), and an ultra-low self-discharge rate (<1% per year), it provides 15-to-20+ years of maintenance-free operational life in utility meters, oceanographic sensors, and defense hardware.
Source: IEC 60086-4 / UL 1642 · Last reviewed Aug 28, 2026
Specs
| Nominal Cell Voltage | 3.60 V |
| Gravimetric Energy Density | 600 – 700 Wh/kg |
| Volumetric Energy Density | 1,000 – 1,300 Wh/L |
| Cycle Life (to 80% Capacity) | Single Use (Primary 20-Year Operational Life) |
| Thermal Runaway Threshold | > 180 °C |
| Operating Temperature Range | -60 to +85 °C |
| Self-Discharge Rate | < 1% / Year (15–20 Year Shelf Life) |
| Primary Anode Material | Metallic Lithium Foil (Li) |
| Primary Cathode Material | Liquid Thionyl Chloride (SOCl2) with Porous Carbon Current Collector |
Passivation Layer & High Energy Retention
Upon construction, a microscopic lithium chloride (LiCl) passivation film automatically forms on the metallic lithium anode. This protective film stops internal parasitic chemical reactions, enabling an unmatched shelf life exceeding two decades. When a load is applied, the passivation layer breaks down within milliseconds to deliver power.