Why effcient batteries matter: an interview with Shin Kyung-soo

To balance the rising human demand for energy and our responsibility to achieve net zero, battery researchers play a large role in improving sustainability and efficiency of batteries. One such researcher is Shin Kyung-soo, who shared how efficient batteries take steps toward net zero and its key role in collaboration with existing renewable energy systems.

What specific field are you currently researching?

I research the materials that go into battery composition, including positive and negative electrodes, and electrolytes. I study which materials are efficient when used in certain systems, what advantages they bring, and if I discover drawbacks, I strategize ways to overcome them to improve battery performance.

Among what you’ve studied in physical chemistry, which part do you think connects the most with climate change?

So, although my department is physical chemistry, my research area is in batteries. That means I deal with the chemical changes that happen inside batteries. Batteries are energy storage systems. Historically, since the Industrial Revolution, we’ve used coal and fossil fuels, which emit CO2 and other carbon emissions, especially with the increased use of gasoline cars. This has caused environmental pollution and global warming. But batteries store and use electrical energy, not fossil fuels, so they can be eco-friendly.

The important point, however, is how the energy used to charge those batteries is produced. If you’re charging an EV with electricity generated by burning coal, then it’s meaningless—you’re just shifting the emissions around. For battery systems to truly be clean and sustainable, they must be charged using renewable sources like wind, tidal, or solar energy.

So, while my work doesn’t directly stop climate change, it contributes indirectly by creating systems that can efficiently store renewable energy. That’s why batteries are so important. For example, during the daylight when energy demand is high because people are running air conditioners, renewable energy like wind can be sent out immediately. But at night, when demand drops yet wind turbines keep generating, that excess energy must be stored. That’s where batteries play a crucial role.

If battery efficiency improves, can that specifically help reduce carbon emissions?

Yes, improved efficiency reduces emissions. Say we need 100 units of energy. If we generate 100 and store it, but the system only lets us use 90, then we’re wasting 10 units. If battery performance improves and we can use 95 instead, that’s more efficient, meaning we consume less energy overall. That translates into fewer carbon emissions. 

Batteries don’t directly eliminate CO2 because they don’t produce energy and just store it, but they are essential for carbon neutrality because they make renewable energy usable on a large scale.

Then what is the biggest challenge in improving battery efficiency?

The first issue is safety. Current batteries carry a risk of explosion because they use liquid electrolytes, which are organic solvents like flammable oil. In these batteries, if combustion happens inside, the battery can burst. That’s why there’s research into all-solid-state batteries, which replace liquid electrolytes with solid ones. But there are still technical barriers—for example, slower charging speeds or shorter battery lifecycles.

The second challenge is acquiring raw materials. For instance, the cathodes use materials like lithium cobalt oxide or lithium nickel. But from a societal perspective, there are reports that cobalt mining in Africa exploits child labor. So there’s a need to either use alternative materials or ensure proper ethical supply chains.

The third and a common challenge is cost. Lithium prices are rising, and in the AI era, where massive energy storage is crucial, lowering costs while maintaining performance is essential.

You mentioned renewable energy earlier. How important are batteries when it comes to switching to renewables or using EVs?

In electric vehicles, batteries are absolutely essential because the whole point of EVs is not to use gasoline. Right now, the two alternatives are hydrogen fuel cells or batteries. Hydrogen fuel cells do work but aren’t widely commercialized yet, so batteries are the most promising alternative.

But again, where the electricity comes from is critical. If coal is burned to generate the electricity that charges EV batteries, it’s basically the same as burning gasoline. So while batteries don’t directly cut emissions, they are inseparable from renewable systems like wind, solar, or tidal power. These systems all have to work together.

Since collaboration with renewable energy systems is needed, do you work with researchers in those fields as well?

Not directly. Renewable researchers focus on energy production—like materials that convert sunlight into electricity, or systems for wind turbines. Engineers then transmit that electricity through power lines, which eventually gets stored in batteries.

So, while our work complements each other, we don’t really collaborate directly. They produce the energy and we provide the storage. In large-scale storage, there’s something called an ESS (Energy Storage System), which stores electricity for later use. That’s where batteries come in.

So far in your research, have you faced financial difficulties or lack of government policy support?

Yes. For example, in China, EVs grew rapidly thanks to heavy government subsidies. Gasoline cars have been around for over a century, so their efficiency is very high. EV technology, on the other hand, is relatively young, maybe 10 to 15 years of development, so it is hard to catch up to gasoline cars' efficiency. To encourage adoption, EVs had to be cheap, and subsidies helped with that.

But now, subsidies are being phased out. Governments are saying how our technology should be advanced enough by now to compete on our own. That means the EV industry must stand financially independent, but technology still needs improvement to lower costs and make EVs attractive without subsidies.