Solid-state battery
A solid-state battery uses solid electrodes and a solid electrolyte, instead of the liquid or polymer gel electrolytes found in lithium-ion or lithium polymer batteries.
All-solid-state battery with a solid electrolyte between two electrodes | |
| Specific energy | Thin film type300–900 Wh/kg (490–1,470 kJ/lb) bulk type 250–500 Wh/kg (410–820 kJ/lb) |
|---|---|
| Self-discharge rate | 6%ｰ85 °C (month) |
| Cycle durability | 10,000-100,000 cycles |
| Nominal cell voltage | bulk type 2.5 V, Thin film type 4.6 V |
| Operating temperature interval | -50 °C 〜 125 °C |
| Charge temperature interval | -20 °C 〜 105 °C |
While solid electrolytes were first discovered in the 19th century, several issues prevented widespread application. Developments in the late 20th and early 21st century generated renewed interest in the technology, especially in the context of electric vehicles.
Solid-state batteries can use metallic lithium for the anode and oxides or sulfides for the cathode, increasing energy density. The solid electrolyte acts as an ideal separator that allows only lithium ions to pass through. For that reason, solid-state batteries can potentially solve many problems of liquid electrolyte (i.e. the mainstream type of) Li-ion batteries, such as flammability, limited voltage, unstable solid-electrolyte interphase formation, poor cycling performance, and strength.
Materials proposed for use as electrolytes include ceramics (e.g., oxides, sulfides, phosphates), and solid polymers. Solid-state batteries are found in pacemakers, and in RFID and wearable devices. Solid-state batteries are potentially safer, with higher energy densities. Challenges to widespread adoption include energy and power density, durability, material costs, sensitivity, and stability.