What is the Difference Between Supercapacitors and Batteries?

Supercapacitors vs Batteries

Comparing supercapacitors and lithium-ion batteries is like comparing sprinters to marathon runners.

Both serve the purpose of storing energy, but they have different advantages and disadvantages.

What are Supercapacitors?

Supercapacitors store energy through two mechanisms: electrostatic and electrochemical.

In electrostatic storage, charges are separated at the electrode-electrolyte interface, forming an electric double layer of ions. This double-layer capacitance stores energy without chemical reactions in the cell.

Energy stored in this way can be discharged immediately when needed. Electrochemical mechanisms involve redox reactions, with ion movement between the electrolyte and electrodes accumulating charge.

Depending on the intended application, supercapacitors can utilize one or both mechanisms.

What are Lithium-ion Batteries?

Lithium-ion batteries are the most common type of rechargeable battery. They store electricity through electrochemical processes, converting electricity into chemical energy and back as needed. Lithium-ion batteries, with the highest energy density per volume and weight, are suitable for portable high-energy-density storage systems. They are used in various devices, from electric vehicles to smartphones and laptops.

Advantages and Disadvantages of Supercapacitors and Lithium-ion Batteries

• Energy Density: Supercapacitors have significantly lower energy storage per unit volume or weight compared to traditional batteries. In EVs, energy density translates to driving distance per charge. Thus, batteries are more suitable for applications requiring large energy storage.
  
• Power Density: Supercapacitors can supply a large amount of energy quickly, making them ideal for applications requiring rapid power usage, such as electric vehicle acceleration and camera flashes.
  
• Self-discharge: The self-discharge rate of batteries is significantly lower than that of supercapacitors. Therefore, batteries are more suitable for applications needing long-term energy storage without frequent recharging.
  
• Lifespan: Supercapacitors can handle over 1,000,000 charge/discharge cycles, while typical batteries last about 2,000-3,000 cycles due to component corrosion by chemical reactions.
  
• Cost: Supercapacitors generally have a higher cost per watt due to component costs and potentially inefficient rapid power discharge.
  
  
• Sustainability: Mining lithium, nickel, and cobalt for lithium-ion batteries raises environmental concerns over waste and pollution. In contrast, supercapacitors can use more sustainable materials, like activated carbon from renewable biomass sources, with less environmental harm and easier recycling.

Which Technology is Best?

The choice between supercapacitors and batteries depends on the application. Both offer significant value and sometimes work optimally together.

For example, in a bus equipped with both:

• During acceleration: Supercapacitors provide a burst of power instantly.
• When maintaining a constant speed: Batteries take over power supply.

However, much research is still needed for both batteries and supercapacitors. Research focuses on:

• Increasing energy density
• Enhancing discharge capacity
• Improving cycling durability
• Enhancing safety

These studies are expected to lead to new materials and chemistries that further improve battery and supercapacitor performance.

Analytical Equipment for Supercapacitor and Battery Research

At Malvern Panalytical, we offer a wide array of reliable, accurate, and versatile tools to help researchers and manufacturers develop high-performance batteries and supercapacitors with a reduced environmental footprint.

For example, the Zetium and Epsilon series X-ray fluorescence analyzers can analyze elemental composition and impurities of cathode, anode, and electrolyte materials.

The Mastersizer series and Zetasizer Advance series allow for the assessment of particle properties such as size and distribution.

Empyrean and compact Aeris X-ray diffractometers can analyze supercapacitor and battery materials for crystalline defects adversely affecting performance. For more details on how Malvern Panalytical’s solutions can accelerate energy storage materials research, visit this page.