Zinc-Air
Battery Chemistries · 9 specs
Direct Answer
Zinc-Air is an open-cathode primary battery chemistry that utilizes atmospheric oxygen as the active cathode material. Because the cathode reactant does not need to be stored inside the cell, Zinc-Air achieves exceptional gravimetric energy densities of 400–500 Wh/kg and volumetric densities up to 1,400 Wh/L, making it the universal standard for hearing aids.
Source: IEC 60086-2 (PR Series) · Last reviewed Aug 28, 2026
Specs
| Nominal Cell Voltage | 1.40 – 1.45 V |
| Gravimetric Energy Density | 400 – 500 Wh/kg |
| Volumetric Energy Density | 1,100 – 1,400 Wh/L |
| Cycle Life (to 80% Capacity) | Single Use (Activated upon seal removal) |
| Thermal Runaway Threshold | > 200 (Safe) °C |
| Operating Temperature Range | 0 to +50 °C |
| Self-Discharge Rate | < 2% / Year (Sealed) | Drains in 2–4 Weeks (Unsealed) |
| Primary Anode Material | High-purity Zinc Powder (Zn) |
| Primary Cathode Material | Atmospheric Oxygen (O2) via Gas Diffusion Membrane |
Adhesive Tab Activation & Atmospheric Sensitivity
Zinc-air cells are manufactured with an airtight protective adhesive tab covering the cathode air intake holes. Once the tab is removed, ambient oxygen enters the porous carbon diffusion membrane and activates the chemical reaction. Because the cell breathes ambient air, its operational life once activated is influenced by environmental humidity and carbon dioxide exposure, typically lasting 1 to 4 weeks once unsealed.