Researchers Reveal Hidden Bottleneck, Reworked Electrolyte Lab Cell Reached 80% Charge in 12.8 Minutes

University of Maryland researchers have identified a previously overlooked factor limiting electric vehicle battery fast charging. Published in Science, their findings show how electro-osmotic drag can restrict lithium-ion movement during charging. By modifying the battery electrolyte, the team achieved an 80% charge in 12.8 minutes in a laboratory cell.

Led by Chang-Xin Zhao in the laboratory of Distinguished University Professor Chunsheng Wang, the researchers found that lithium ions pull solvent molecules through the electrolyte as they move. At high charging rates, solvent can leave the battery’s porous positive electrode faster than it can return. This depletion reduces conductivity, increases resistance and limits current flow.

The problem is particularly significant in thick, energy-dense electrodes, where ions and solvent must travel longer paths. One conventional approach has been to use thinner electrodes, but that can reduce energy density and driving range.

The Maryland team addressed the problem by adding fluorine-containing chemical groups to solvent molecules in the electrolyte. This modification weakened the attraction between the solvent and lithium ions, reducing solvent loss from the positive electrode and helping it return during charging.

In a 4-ampere-hour pouch cell, the modified electrolyte enabled an 80% charge in 12.8 minutes and a 90% charge in 14.7 minutes. The University of Maryland reported that the improvement did not compromise energy density.

The findings could help battery manufacturers develop EV batteries that combine longer driving range with shorter charging stops. However, the results were demonstrated in a laboratory cell. Further testing is needed to establish commercial performance, durability, cost and scalability in automotive battery packs.

EVinfo.net’s Take: Battery Breakthroughs Could Accelerate EV Adoption

Numerous battery studies are demonstrating improvements in energy density, charging speed, battery lifespan, safety, and overall performance. If these advances coincide with the commercialization of solid-state batteries, the potential impact on electric vehicle adoption could be significant.

Solid-state batteries promise as much as twice the driving range of conventional lithium-ion batteries with the same battery size and weight. That could address one of the biggest barriers to EV adoption: driving range. Automakers could offer substantially longer-range vehicles without adding battery weight, increasing vehicle size, or requiring larger battery packs.

Combined with faster charging, lower costs, improved durability, and better safety, these developments could make EVs considerably more attractive to mainstream consumers. As battery technology continues to advance, the next generation of electric vehicles could deliver capabilities that were difficult to imagine just a few years ago.

If solid-state battery breakthroughs deliver on their promise, they could become a major catalyst for accelerating EV adoption worldwide.