Supercapacitors versus batteries: Which is superior? This post is going to compare supercapacitors and batteries.
Although supercapacitors have been around since the 1950s, their full potential has only recently come to light. Let’s look at these computer parts that store energy similarly to batteries but according to entirely different tenets. Many people think they’re related to lithium-ion batteries.
We’ll outline the basics of supercapacitors vs batteries and break down their advantages and disadvantages as a storage medium.
What is a Supercapacitor?
Supercapacitors are high-capacity capacitors, to put it briefly. They function somewhere between rechargeable batteries and electrolytic capacitors in terms of functionality and have higher capacitance and lower voltage limits than other types of capacitors.
What this means in practice is that they:
- Charge much faster than batteries
- Can store much more energy than electrolytic capacitors
- Have a lifespan (measured in charge/discharge cycles) somewhere between the two (more than rechargeable batteries and less than electrolytic capacitors)
Consider the fact that lithium-ion batteries typically have between 500 and 10,000 charge cycles, whereas electrolytic capacitors have an unlimited number of charge cycles. However, the lifespan of super- and ultracapacitors varies from 100,000 to 1,000,000 cycles.
The benefits of supercapacitors include:
- Balancing energy storage with charge and discharge times. Supercapacitors can make up for their lower energy storage capacity—roughly ¼ that of a lithium-ion battery of comparable size—by charging more quickly. In some instances, they charge batteries with comparable capacities more quickly than 1,000 times faster. Supercapacitors allow for almost instantaneous charging of some electric toys. Similar thinking is being attempted by businesses like Nawa in actual electric vehicles. If supercapacitors were used to power electric vehicles instead of rechargeable batteries, they could be fully charged in a fraction of the time it takes to fuel a fossil fuel vehicle. This would eliminate the need for the long charging times associated with battery-powered vehicles.
- Wide-ranging Operating Temperatures. Supercapacitors have a much broader effective operating temperature (from roughly -40F to +150F).
However, the rate of energy exchange has both a bug and a flaw. Here are some disadvantages of supercapacitors:
- Self-discharge rate. Supercapacitors are not suitable for long-term energy storage. Supercapacitors can self-discharge up to 10% to 20% of their charge per day, which is a significant increase over lithium-ion batteries’ discharge rate.
- Gradual voltage loss. While capacitors’ voltage output decreases linearly with charge, batteries’ voltage output remains nearly constant until they run out of power.
How Do Capacitors and Batteries Differ?
In that they both have the ability to store electrical power and then release it when necessary, capacitors and batteries have a lot in common. Batteries use a chemical reaction to store energy that is later released, whereas capacitors store energy as an electrostatic field.
An electrolyte sits in between the anode and cathode terminals inside a battery. A substance with ions is known as an electrolyte, which is typically a liquid. A particle with an electrical charge is called an ion.
Additionally, the electrolyte contains a separator that only lets ions pass through it. Ions transfer from one side of the separator to the other as you charge the battery. The opposite occurs when the battery is discharged. The movement of ions chemically stores electricity or turns that stored chemical energy back into an electric current.
Are Supercapacitors the Future of Energy Storage?
It appears likely that supercapacitor batteries will be available in the future given the direction supercapacitor research is heading. These would be gadgets that possessed the speed, sturdiness, and energy density of supercapacitors with the operating time and long battery life of batteries.
2016 saw the development of a flexible supercapacitor prototype by University of Central Florida researchers that had a higher energy density than existing supercapacitors and could withstand 30,000 charge cycles without losing performance.
New materials on the nanoscale and experiments with graphene all point towards the possibility that supercapacitors with much higher energy densities are possible. Even if they never match lithium-ion batteries, having a usable amount of charge and a quick recharge time may allow them to replace batteries in some situations.
Supercapacitors are competing with other technologies, though. The most significant of these is the storied solid-state battery, though recently, conventional lithium-ion batteries with graphene infusions have also demonstrated promise. Whichever fast-charging, durable, energy-dense technology wins the race, we’ll all be winners.
Conclusion: Supercapacitors Vs. Batteries
Supercapacitors fall somewhere between traditional electrolytic capacitors and rechargeable batteries in lifespan, energy storage, and efficient operating temperature.
Where is there enough room for both? The answer to batteries or supercapacitors is frequently both. When the supercapacitors are flexible and integrated into the system or product, there is enough room.
The solution is to install flexible supercapacitors inside the existing power cords, distributed throughout the rest of the infrastructure, to supplement the existing batteries in the space designated for energy storage systems.
Why Not Use Supercapacitors Instead of Batteries?
Unfortunately, however, supercapacitors still have two main problems that remain since their inception: they can store 10-50 times less energy per kilo/liter than batteries (i.e. they are very bulky) and they are very expensive. As a result, the supercapacitor industry has never really thrived.
Are Supercapacitors Safer Than Batteries?
Supercapacitors are safer than batteries in terms of the above risk factors. Supercapacitors could potentially suffer harm if they are charged at a voltage higher than their rated capacity. However, it can become a difficult task when charging multiple capacitors.