Researchers at Cornell have developed a new fast-charging, long-duration lithium a new lithium battery that can charge in less than five minutes—faster than any such battery on the market—while maintaining stable performance over extended cycles of charging and discharging. A paper on their work is published in the journal Joule.

Jin et al.

Electrode materials that enable lithium (Li) batteries to be charged on timescales of minutes but maintain high energy conversion efficiencies and long-duration storage are of scientific and technological interest. They are fundamentally challenged by the sluggish interfacial ion transport at the anode, slow solid-state ion diffusion, and too fast electroreduction reaction kinetics.

Here, we report that Li alloy anodes based on indium (In) exhibit fast Li surface and bulk diffusivities but moderate electroreduction reaction rates. The resultant LiIn anodes appear to belong to a unique class of inherently low second Damköhler (Da) number (LDA_II) materials, which are predicted to exhibit high Li reversibility at unconventionally high charge rates.

We demonsterate this capability using Li-ion battery cells in which LiIn anodes are paired with a range of intercalation (e.g., LiFePO₄ and LiNi_0.8Co_0.1Mn_0.1O₂), and conversion (e.g., I₂and O₂) cathode. We show that such cells manifest excellent fast charging capabilities in a range of electrolyte solvents.

—Jin et al.

After fast charging their new lithium battery, the researchers observed its indium anode had a smooth lithium electrodeposition, whereas other anode materials can grow dendrites that impact the battery’s performance.

For the new lithium battery, the researchersfocused on the kinetics of electrochemical reactions, specifically employing a chemical engineering concept termed the “Damköhler number.” This is essentially a measure of the rate at which chemical reactions occur, relative to the rate at which material is transported to the reaction site.

Identifying battery electrode materials with inherently fast solid-state transport rates, and hence low Damköhler numbers, helped the researchers pinpoint indium as an exceptionally promising material for fast-charging batteries. Indium is a soft metal, mostly used to make indium tin oxide coatings for touch-screen displays and solar panels. It is also used as a replacement for lead in low-temperature solder.

The new study shows indium has two crucial characteristics as a battery anode: an extremely low migration energy barrier, which sets the rate at which ions diffuse in the solid state; and a modest exchange current density, which is related to the rate at which ions are reduced in the anode. The combination of those qualities—rapid diffusion and slow surface reaction kinetics—is essential for fast charging and long-duration storage.

The key innovation is we’ve discovered a design principle that allows metal ions at a battery anode to freely move around, find the right configuration and only then participate in the charge storage reaction. The end result is that in every charging cycle, the electrode is in a stable morphological state. It is precisely what gives our new fast-charging batteries the ability to repeatedly charge and discharge over thousands of cycles.

—Lynden Archer, corresponding author

That technology, paired with wireless induction charging on roadways, would shrink the size—and the cost—f batteries, making electric transportation a more viable option for drivers.

However, that doesn’t mean indium anodes are perfect, or even practical.

While this result is exciting, in that it teaches us how to get to fast-charge batteries, indium is heavy. Therein lies an opportunity for computational chemistry modeling, perhaps using generative AI tools, to learn what other lightweight materials chemistries might achieve the same intrinsically low Damköhler numbers. For example, are there metal alloys out there that we’ve never studied, which have the desired characteristics? That is where my satisfaction comes from, that there’s a general principle at work that allows anyone to design a better battery anode that achieves faster charge rates than the state-of-the art technology.

—Lynden Archer

The research was supported by the US Department of Energy Basic Energy Sciences Program through the Center for Mesoscale Transport Properties, an Energy Frontiers Research Center. The researchers made use of the Cornell Center for Materials Research, which is supported by the National Science Foundation’s Materials Research Science and Engineering Center program.

Resources

• Shuo Jin, Xiaosi Gao, Shifeng Hong, Yue Deng, Pengyu Chen, Rong Yang, Yong Lak Joo, Lynden A. Archer (2024) “Fast-charge, long-duration storage in lithium batteries,” Joule, doi: 10.1016/j.joule.2023.12.022