It’s easy to think of capacitors and batteries as related – after all, they both store electricity – but the methods they use to achieve this common goal are quite different. Below is a chart that summarizes the differences between supercapacitors and lithium-ion batteries:
Supercapacitor vs Battery Chart
Comparing these two devices is useful because lithium-ion batteries are the most common type of rechargeable battery today, and supercapacitors are their nearest analog in the capacitor world.
As you can see from the chart, these two devices differ in a couple of fundamental ways.
Differences Between Capacitor and Battery
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Batteries excel at storing energy, while supercapacitors rate better for power. In practical terms, this means that supercapacitors are better at discharging their stored energy quickly, while batteries save more energy in the same amount of material. Batteries also maintain a near-constant voltage output until they die, while supercapacitors’ voltage output decreases gradually as they discharge.
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Supercapacitors have a much longer lifespan by number of charge cycles. The supercapacitor with the shortest lifespan is still an order of magnitude ahead of the longest-living standard battery. On the other hand, because supercapacitors charge and discharge so much more rapidly than batteries, their working life is liable to be only 150-200 percent that of a battery (by completing cycles more quickly). In a vehicle, for instance, a Li-ion battery may last five to ten years, while a supercapacitor would last ten to fifteen.