A capacitor capable of storing 19 times more energy than current ones was accidentally discovered in a laboratory.

• Ferroelectric capacitors can charge and discharge electricity at ultra-fast speeds.

• With this accidental discovery made in the United States, its weakest point was solved: energy density.

Intuition is a pillar of science that receives little attention. Penicillin, X-rays and microwaves were discovered by accident. Now, a group of scientists, unwittingly, have designed a capacitor with an energy density 19 times greater than the current ones.

A little context. Unlike batteries, which take time to charge and discharge, capacitors can store electricity in an electric field and discharge it quickly. Modern electronic devices contain hundreds of capacitors.

High-performance systems such as electric vehicles require capacitors that can charge and discharge electricity at ultra-high rates. Ferroelectrics have this advantage, but their energy density, or the amount of electricity they can store, is too low for such powerful systems.

A chance find. Barium titanate is one of the most studied ferroelectrics. It does not store much energy because its crystalline structure tends to collapse when exposed to heat.

Inspired by previous research, Korean researchers at the University of Washington and the Massachusetts Institute of Technology have developed a “heterostructure” of barium titanate embedded in layers of very thin semiconductor.

Without looking for it, they discovered that electricity accumulates at the points of contact between different materials, increasing the time it takes for the structure to return to its original state.

After testing several options, the researchers eventually created a structure with two layers of molybdenum disulfide and one layer of barium titanate that can store a lot of energy with little loss.

Tiny sandwich. A study published in the journal Science explains that the relaxation time of capacitors can be increased using a 2D/3D/2D heterostructure, in which a ferroelectric material is sandwiched between two layers of flat material.

The two materials are arranged in an atomic-scale sandwich such that they are intertwined with chemical and non-chemical bonds to form a structure 30 nanometers thick (30,000 times thinner than a hair).

This approach of physical and chemical balance between conductivity and nonconductivity not only minimizes energy loss, which has been a major problem with capacitors based on dielectric materials, but also preserves the crystalline structure of the ferroelectric component.

Because it’s important. Using this method, the researchers were able to create a structure capable of storing 191.7 joules of energy per cubic centimeter, of which more than 90% can be used.

According to the inventors, the new structure has an energy density 19 times greater than that of other capacitors.

This big jump in capacitor efficiency could extend the battery life of electronic devices, electric vehicles, or large battery storage systems for a power grid that must respond quickly to electricity demand and daily fluctuations in renewable energy production. .

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