Quantum Battery: The Future of Energy Storage

Written by Devvrat Tiwari, Ph.D. Student at Indian Institute of Technology, Jodhpur, India

Battery, which is an energy storage device, plays a very important role in our lives. As we move towards greener solutions for transport, it is going to play an even more important role in the future. However, current conventional batteries are not sufficient in supplying energy fast enough. Charging takes time, and the heaviness of the battery also takes up space in vehicles.

To tackle most of issues related to the conventional battery, researchers are developing a new kind of battery called a quantum battery. Do you know what a quantum battery is? This article is all about this newly evolving technology called the quantum battery.

Quantum battery is an energy storage device, similar to the batteries in our mobile phones. The key difference is how quantum batteries do the charging and discharging. Also, the size of a quantum battery is very small compared to conventional batteries (e.g., Li-ion batteries that we are using in every electronic system) and is typically at the molecular or atomic level (to be quantitative: angstrom or nanometer scale).

You might ask, how can we use these tiny quantum batteries in our daily life? Or, what are the applications of quantum batteries? why should one care about it? Let’s dive into it.

Why should one care about quantum battery?

Imagine taking a sip of your coffee and having a fully charged phone. Quantum batteries can make ultra-fast charging a reality. Recently, electric vehicles have become the future of transport. A quantum battery might be able to pack more energy into smaller packages, leading to lighter electric vehicles, and the wait time for charging an electric vehicle will also be reduced.

Further, we daily encounter many gadgets that run on a battery. With quantum batteries, these gadgets will charge faster and last longer. In summary, our shift towards renewable energy will become more efficient using quantum batteries, and we can change how we charge and power our world.

How do quantum batteries work?

Quantum batteries work by storing and delivering energy through quantum mechanical systems like atoms, qubits, etc. They are not dependent on chemical reactions in the way classical batteries work. Let’s take an example of atom as a quantum battery and discuss how it works.

We all know that atoms consist of a nucleus around which electrons revolve. The energy levels of electrons are quantized. It can have only definite energy states governed by quantum mechanics. If an atom is in its ground state, it means all the electrons are in their allowed positions at minimum energy.

Once we excite the atom by some external influence, say by laser light, one of the electrons can absorb the photon and go to an excited state, meaning a higher allowed energy level. In this condition, we say the atom is in an excited state.

We can describe the atom in an excited state as a charged quantum battery. Once the electron comes back to its ground energy state by emitting the energy, we say that the quantum battery is discharged. People who know a bit of physics might ask how you make the charged state stable because, spontaneously, the electron will try to come back to its ground state by emitting a photon equal to the energy gap between the two states.

Researchers are working very hard to make the excited state last longer. These challenges are being addressed by various research groups.

So, for quantum battery formation, we need two systems: one is the quantum battery, and the other is the system to charge this quantum battery. Chargers of quantum batteries, we call them quantum chargers, are also quite different from their classical sense. Quantum chargers interact with the atom/quantum battery to charge it by different means, such as laser pumping, spin coupling and cavity modes.

Also, Quantum batteries utilize two basic properties of quantum mechanics in the total functioning of it, which are the superposition and entanglement. Superposition is like a coin flipping in the air, it’s not just heads or tails, but kind of both until it lands. Thus, you can say that the quantum batteries are in the superposition of both charged and discharged state, until measured. This property can be unlocked for future quantum logic gates.

Similarly, entanglement is like two best friends getting affected by each other’s actions, no matter how far they are. What happens if we connect multiple quantum batteries together? If they are properly entangled and coupled via the right interactions, they can undergo collective charging, where energy is distributed across the entire system simultaneously. However, this kind of quantum speed-up requires specific global interactions, entanglement alone is not sufficient. Each individual quantum battery must be engineered to support such interactions for the collective effect to be viable. An entangled state allows multiple battery units to behave coherently. Therefore, quantum batteries offer the potential for a much faster charging time.

Notably, these quantum batteries also interact with their ambient environment, leading to dissipation of the stored energy inside the battery. Interestingly, however, not all environmental noise is bad; some may help stabilize the quantum battery [1, 2].

Recent research and what is next?

The formal research on quantum batteries began with Alicki and Fannes’ article in 2013. Subsequently, researchers began exploring how quantum effects may benefit the quantum battery’s storage capacity, charging time, and efficiency.

The impact of noise on the quantum battery and its mitigation were subsequently studied. Recent studies have focused on envisaging various quantum systems as a quantum battery. Further, the effects of charger–battery interaction strength and non-Markovian evolution (quantum systems recovering information lost to the environment unavoidably) have recently been explored.

Quantum batteries are still in the lab: experimental work in quantum batteries is still in its infancy, and a fully operational proof of principle is yet to be demonstrated but their promise is enormous.

Upon overcoming challenges like control, scalability, noise, and stability, we could soon have batteries that charge in seconds, last longer, and fit into tiny spaces. These breakthroughs may power wearable devices, electric vehicles, and our everyday lives.

Further Reading:

1. D. Tiwari, B. Bose, S. Banerjee (2025). Strong coupling non-Markovian quantum thermodynamics of a finite-bath system. J. Chem. Phys. 162, 114104. doi: https://doi.org/10.1063/5.0254029

2. M. Yadav, D. Tiwari, and S. Banerjee (2025). (Thermo-)dynamics of the spin boson model in the weak coupling regime: Application as a quantum battery. arXiv preprint arXiv:2504.15712. doi: https://doi.org/10.48550/arXiv.2504.15712