Ton of progress?

I would refer to that as "research ongoing but no progress yet".

The big problem is the higher the energy density the greater the release of energy in a catastrophic failure. For example if you were to increase energy density ten fold, then the release of energy due to catastrophic damage to the battery would be ten fold. Materials aren't even in the consideration, it's going to be an explosion.

We'd certainly welcome an EV battery that weighs greatly less, but safety is always going to be a forefront issue only by the physics of energy storage.

Still there needs to be a lot of improvement. I think the weight issue is the outstanding one. Higher energy density and greater longevity would certainly be welcome, but I think safety will always be skirting the edge. It's not been a fast track toward these goals, but it's still come a good way. Unfortunately I expect lithium-ion technology to hit a wall sooner than later.

Home gas & electric installations are a lot safer today than they once were. They're actually a great example of how a dangerous power source can be made a lot safer through better choices and engineering.

The first gas ovens and heaters used coal gas, which is carbon monoxide and hydrogen. The monoxide meant that coal gas was highly poisonous to breathe; and both monoxide and hydrogen are odorless — so you might not know the oven was left on unlit and killing your family.

Modern natural gas is mostly methane, with an unpleasant scent added so we can detect leaks. Methane is unbreathable, but still a lot safer to have in your house than monoxide!

(To be clear, the monoxide was not a contaminant; it's a fuel. Coal gas burns into carbon dioxide and water, just like methane.)

So here, we got a better gas technology: in fact, we got a whole different gas; a fundamentally safer-for-humans one — and on top of that, added an extra safety mechanism in the form of an odorizer, making the gas stinky instead of odorless.

Same goes for electricity. Modern home electrical outlets are grounded, greatly reducing the chance of a dangerous shock due to a wiring problem or a defective appliance. And modern circuit breakers are much more reliable than the fuses they replaced; and they don't break, so the homeowner doesn't have an incentive to defeat the safety device the way folks often did with fuses.

And modern kitchen & bathroom outlets have GFCIs, so an appliance shorting out through water (or your body) will break the circuit.

So here, we've gotten better electrical technology too: grounded outlets, circuit breakers, and GFCIs all make electricity much safer than when it was first installed in homes.

To put it morbidly: Coal-gas ovens and ungrounded electrical appliances were both once common means of suicide. Their modern replacements are safe enough that they don't work for that anymore. Same goes for cars, by the way. Modern gasoline cars don't put out enough monoxide to kill a person rapidly by inhaling the exhaust.

So yeah, I think it's perfectly reasonable to say we need a better battery technology, ideally one that doesn't do this sort of thing.

It seems to me that one simple (and therefore probably wrong) solution to e-waste would be to have retailers, distributors, and manufacturers accept nonworking or obsolete devices for responsible disposal or recycling.

Turn the one-way supply chain bidirectional. If you sell it, you've gotta take it back when it's broken. If you have an assembly line for making it, you can make a disassembly line for taking it apart. If that's expensive, well, apply some ingenuity to making it cheaper.

Want to deal with fewer broken devices? Make devices that don't break so much.