A few of us on the Peaxy team recently attended a talk entitled “The Future of Energy Storage” by MIT professor Yet-Ming Chiang, for the MIT Club of Northern California. For those interested in batteries and energy storage, it’s well worth watching the recorded hour-long session (you can skip ahead to 12:50 and watch until the Q&A begins).
Here are a few of our key takeaways from the talk:
Even though lithium-ion technology has been around for decades, we’ve only scratched the surface of its full potential. While theoretical energy densities are very high (3,000 watts/kg), the Tesla Model S battery pack, for example, is only around 150 watts/kg.
The energy demands on a battery are drastically different depending on the use cases in different industries. Electric vertical-lift aircraft, for example, require huge power spikes on take-off and landing, representing a much wider swing than the requirements for an electric car or truck. Lithium-ion batteries need to be developed that can deliver a high discharge of power for extended durations for this type of scenario.
Another example is renewable energy storage, where a gap still exists between lithium-ion and natural gas, based on the cost per kilowatt hour. The challenge is to develop a lithium-ion battery that can hold a high state of energy charge over a period of 20 years before being replaced. A breakthrough is required to get lithium ion technology below the $100/KW barrier.
The main challenge in increasing energy density in lithium-ion batteries is achieving a solid state battery that relies on metal rather than liquid to transport lithium ions. Research is underway to use lithium metal, as it offers benefits around both ambient temperature and an overall reduced size, critical in certain applications.
If efforts to electrify transportation and renewable energy storage are to be realized, these gaps need to be bridged. The challenge to get lithium-ion to the next level is complex and multi-faceted, and advancements won’t all come at the same time. A metal electrode is possible within five years.