EV charging

In a newly published study, we describe our design for a self-extinguishing rechargeable battery. It replaces the most commonly used electrolyte, which is highly combustible – a medium composed of a lithium salt and an organic solvent – with materials found in a commercial fire extinguisher. An electrolyte allows lithium ions that carry an electric charge to move across a separator between the positive and negative terminals of a lithium-ion battery. By modifying affordable commercial coolants to function as battery electrolytes, we were able to produce a battery that puts out its own fire. Our electrolyte worked well across a wide temperature range, from about minus 100 to 175 degrees Fahrenheit (minus 75 to 80 degrees Celsius). Batteries that we produced in the lab with this electrolyte transferred heat away from the battery very well, and extinguished internal fires effectively. We subjected these batteries to the nail penetration test, a common method for ass...

In today’s electronic age, rechargeable lithium-ion batteries are ubiquitous. Compared with the lead-acid versions that have dominated the battery market for decades, lithium-ion batteries can charge faster and store more energy for the same amount of weight. These devices make our electronic gadgets and electric cars lighter and longer-lasting – but they also have disadvantages. They contain a lot of energy, and if they catch fire, they burn until all of that stored energy is released. A sudden release of huge amounts of energy can lead to explosions that threaten lives and property. As scientists who study energy generation, storage and conversion, and automotive engineering, we have a strong interest in the development of batteries that are energy-dense and safe. And we see encouraging signs that battery manufacturers are making progress toward solving this significant technical problem. Avoiding overcharging is one way to reduce the ris...

The race to decarbonize passenger cars and light-duty trucks in the U.S. is accelerating. Battery electric vehicles accounted for almost 6% of all new vehicle sales in 2022, up from close to 3% in 2021, and demand is outstripping supply, even as manufacturers roll out new models and designs. The Biden administration is spending billions of dollars to build out EV charging networks and providing incentives for purchasing new and used EVs. This shift offers big economic and environmental benefits, but they’re not spread equitably. People who bear the most burdens in our current transportation systems often receive the fewest benefits, and are least able to change their situations. I study the future of clean transportation and energy, and my research analyzes equity considerations in the design of these systems. As my colleagues and I see it, an equitable transition will require thinking broadly about all transportation users and their needs – especially those who are...

As part of its effort to reduce air pollution and cut greenhouse gas emissions that contribute to climate change, California is pursuing aggressive policies to promote clean trucks. The state already requires that by 2035, all new cars and other light-duty vehicles sold in the state must be zero emission. Its powerful Air Resources Board has adopted rules requiring that most trucks be zero emission by 2035, and is now proposing that all trucks sold by 2040 must be zero emission. The Conversation asked a panel of transportation experts from the University of California, Davis what’s involved in such a rapid transition. 1. Why is California targeting medium- and heavy-duty trucks? Although diesel engines are valuable for moving heavy loads, they also are major polluters. Diesel trucks account for one-fourth of greenhouse gas emissions and about half of conventional air pollution from transportation in U.S. cities. Pollutants in diesel exhaust include nitrogen oxides, fine...

A nationally representative survey of 8,027 Americans shows that across all racial demographics, overall interest in purchasing electric vehicles is high. Among those surveyed, 33% of white respondents, 38% of Black respondents, 43% of Latinos and 52% of Asian Americans say they would “definitely” or “seriously consider” purchasing or leasing an EV as their next vehicle. The survey was conducted by Consumer Reports, with input from the nonprofit advocacy groups GreenLatinos, the Union of Concerned Scientists and EVNoire and administered between Jan. 27 and Feb. 18, 2022, by NORC at the University of Chicago, an objective, nonpartisan research organization. Electric vehicles are critical for reducing transportation emissions, but communities of color currently adopt this key technology at lower rates than white drivers. This survey, for which I was an adviser, helps to shed light on some of the reasons for this disparity. Cleaner air for all Air pollut...