Jeremy Michalek

Still, if I were going to fast charge a lot, I'd prefer LFP.

LFP tends to be used on the lower-range EVs, which are the ones we need to fast charge more often (bonus!).

If I were buying a used EV, I'd also feel batter about an "iron-clad" LFP battery. It keeps going and going and going...

Automakers design battery management systems to protect against early death (e.g. by slowing charging or using less of the battery's capacity), so our standardized lab tests don't necessarily mean that fast charging your NCA/NMC EV will kill its battery.

LFP is cheaper and relies on fewer critical materials (www.nature.com/articles/s41...). Its main disadvantage is lower energy density (shorter range). But since LFP can take so much more abuse, more of its capacity can be used in practice, reducing or eliminating its key weakness

Replacing the battery every time it died would be prohibitively expensive in the extreme cases

Restricting the portion of the battery's capacity that the vehicle can use (as automakers do) can make NMC and NCA batteries last longer, at the cost of reduced range

When we used the entire battery capacity
- Fast charging killed NCA batteries (bottom, used in long range Teslas) rapidly.
- Heavy fast charging also killed NMC batteries (middle, used by most US automakers).
- LFP batteries (top, used in standard range Teslas) can take the abuse.

We cycled NMC, NCA and LFP batteries (the 3 types used in today's EVs) with varying amounts of slow charging (e.g. at home, level 2) and fast charging (e.g. highway rest stop, DCFC).

Quantifying the degradation cost of frequent fast charging across multiple electric vehicle battery chemistries We investigate the relative impact of fast charging on degradation in commercial lithium-ion battery cells with electric vehicle-relevant chemistries …

Will fast-charging kill your EV battery?

We have some answers in our new study, out today
www.sciencedirect.com/science/arti...

w/ Hannah Morin, Jay Whitacre; @cmu.edu

TNCs generally increase VMT relative to personal vehicle travel unless (1) more rides are pooled or (2) personal vehicle travel requires *very* extensive search for parking.

We don't have exactly that comparison in the study, but broadly TNC electrification addresses a smaller portion of externality costs than VMT reduction (because of congestion and collision costs).

“Superb” from Granger Morgan’s take

Trump Is Killing American Innovation China will reap the benefits.

Superb piece by David Victor in @foreignaffairs.com on the strategic national importance of innovation investment, incl. stability, pipeline of ideas, people & scale. www.foreignaffairs.com/united-state...

@destenie.bsky.social

@destenie.bsky.social

Analyzing disparities in app-hailed travel during extreme heat in New York City To understand extreme weather effects on travel behavior, we examine changes in New York City app-hailed travel during extreme-heat days and estimate …

During extreme heat events, urban travelers adjust their transportation choices unequally. Using NY City ride-hailing data, we find wealthy neighborhoods increased trip freq at higher rates than low-income areas. W/ @jmichalek.bsky.social & @cdharper.bsky.social
www.sciencedirect.com/science/arti...

Made me want to vomit

Another example of work I presented at TRB recently that could be targeted now.

We found that ride-hailing technology mitigates effects of driver racial discrimination, but effects of residential segregation persist

www.pnas.org/doi/10.1073/...

Massive implications

Elon Musk’s Blitz Shakes U.S. Government as He Sweeps Through Agencies The billionaire is creating major upheaval as his team sweeps through agencies, in what has been an extraordinary flexing of power by a private individual.

Slow down, and stop breaking things you don’t know how to fix

www.nytimes.com/2025/02/03/u...

Trump signs exec order on 1st day back to “eliminate the EV mandate”.

There was no national EV mandate, but changes to EPA standards and a successful revocation of California’s waiver to set its own policy would have big effects for the country’s top GHG-emitting sector.

I discuss w/ PolitiFact:

YouTube video by The Wall Street Journal What This Iconic Photo Says About America’s Road Planning | WSJ Pro Perfected

@costasamaras.com

youtu.be/z0C7rb9a4mk?...

Yes, update. One from 26 Dec and the other from 2 Jan.

There was an older episode, but these are both new. A focus on the Francesca Gino and Dan Ariely / Data Colada saga.

Can Academic Fraud Be Stopped? (Update) Podcast Episode · Freakonomics Radio · 01/02/2025 · 1h 9m

podcasts.apple.com/us/podcast/f...

Why Is There So Much Fraud in Academia? (Update) Podcast Episode · Freakonomics Radio · 12/26/2024 · 1h 15m

podcasts.apple.com/us/podcast/f...

‼️

Our policy briefs & public comments on EVs and ridehailing

www.cmu.edu/cit/veg/brie...

Yes.

I’ll add that writing is thinking, and concentrated iterative rewriting is where a lot of the key intellectual work gets done.

E.P.A. Allows California to Ban Sales of New Gas-Powered Cars by 2035 The Trump administration is expected to revoke the program, setting up a legal clash between the state and federal government.

The EPA granted California and 11 other states permission to ban the sale of new gasoline-powered cars by 2035. President-elect Donald Trump is expected to revoke the program, part of his pledge to scrap Biden-era climate policies.

New CMU/ANL study on incorporating energy justice and equity objectives in power system models takes a broad look at practices and opportunities across the literature