A hybrid capacitor, also known as a lithium-ion capacitor, is an energy-storage device like an ultracapacitor that can store significantly more energy in the same volume of space as an ultracapacitor. The major difference between the two technologies is in the electrode materials. The positive (cathode) electrode material of a hybrid capacitor is activated carbon, which is identical to that of an ultracapacitor. The negative (anode) electrode material is composed of carbon material doped with lithium (Li+) ions, which enables the higher energy density in a hybrid capacitor versus an ultracapacitor. This electrode formulation enables the hybrid capacitor to have similar life and power capabilities to an ultracapacitor with significantly higher energy density. The chart below gives a direct comparison between ultracapacitors, hybrid capacitors, and lithium-ion batteries:
| Characteristic | Ultracapacitor (TPL-8.0/10x25F) |
Hybrid Capacitor (TPLC-3R8/70MR10x25) |
Lithium-Ion Battery (18650) |
| Nominal Cell Voltage | 2.7V | 3.8V | 3.6V to 3.7V |
| Minimum Cell Voltage | 0 | 2.2V | 2.5V |
| Cathode (+) | Activated carbon | Activated carbon | Lithium metal oxide |
| Anode (-) | Activated carbon | Carbon doped with lithium ions | Carbon |
| Energy Density (Wh/kg) | 2.7 | 36.9 | 230 |
| Energy Density (Wh/L) | 2.05 | 71.5 | 600 |
| Internal Resistance | Low | Low | High |
| Cycle Life | 500,000 to 1 million | 250,000 to 500,000 | 500 to 1,000 |
| Self-Discharge | Moderate | Low | Low |
| Calendar Life | 10+ years | 10+ years | 2 to 4 years |
| Temperature Range | -40°C to +65°C | -25°C to +70°C | 0°C to 45°C |
* Ultracapacitors and lithium-ion capacitors can be operated up to 85°C with voltage de-rating.
Similar to an ultracapacitor, a hybrid capacitor is suitable for both backup-power and pulse-power applications. Due to the higher energy density of a hybrid capacitor, its backup-power duration can be longer than that of an ultracapacitor, with a smaller-sized and lighter-weight hybrid capacitor configuration. In pulse-power applications, the hybrid capacitor is easy to combine with a lithium-ion battery due to their shared operating voltage levels and low self-discharge. This combination allows for downsizing the primary lithium-ion battery and extending its lifetime by protecting the battery from pulse-power events.
When operating hybrid capacitors, it is important to keep in mind that the minimum operating voltage of a hybrid capacitor cell is 2.2V. Going below 2.2V can result in irreversible damage to the cell. Also, hybrid capacitors are charged during the production process and so will be at voltage when shipped from the factory. Care must be taken when handling individual cells to avoid a short circuit, which also means that wave soldering is not an option with hybrid capacitors.
At Tecate Group, we offer single, 3.8V hybrid capacitor cells in a variety of capacitances. These cells come with radial wire leads or a Molex 87439-0200 quick connector for ease of handling. Tecate also offers hybrid capacitor module design services.
