A battery technology that’s getting a lot of attention is solid-state batteries, lithium-ion batteries that replace the liquid electrolyte with a solid material.
To elaborate on why it’s still stuck at TRL 4/9: the barrier is manufacturing, not science. There are several types of solid electrolyte — the component that defines an all-solid-state battery — and each is a different trade-off between performance and cost.
The leading candidate, the sulfide type, has the highest conductivity, and Japan’s decades-deep players (Toyota, Idemitsu) are built around it. But it reacts with trace moisture to release H₂S, so it needs extremely strict dry-room control — a serious manufacturing-cost barrier, not a physics one.
The halide type is the development to watch. In July, Sumitomo Chemical announced it will mass-produce a halide electrolyte that — it says — matches sulfide conductivity while running on existing lithium-ion production lines. That prioritizes manufacturability over the spec sheet.
One issue I had hoped you might address is how the ions migrate through a solid electrolyte (as opposed to the liquid case where mobility of dissolved material is not a problem).
I'd never really registered that a gas car gets its oxidizer for free from the air while a battery has to carry its own. That framing explains the energy density gap better than any spec sheet: solid-state trims the scaffolding, but the cathode you have to haul around isn't going anywhere.
Your application of the virial theorem seems wrong. Batteries are presumably not in equilibrium when (dis)charging, and they're more than 50% efficient.
I've seen Indian software engineers in battery-adjacent fields over-invest in RSUs of solid-state battery startups, assuming commercialization will mirror the hype timeline.
CATL's 4/9 readiness suggests a 5-10 year horizon at least — long enough that relying on it for near-term retirement growth is risky.
The pattern: treat it as a speculative allocation, not a core holding. Run the numbers on a 10-year delay.
To elaborate on why it’s still stuck at TRL 4/9: the barrier is manufacturing, not science. There are several types of solid electrolyte — the component that defines an all-solid-state battery — and each is a different trade-off between performance and cost.
The leading candidate, the sulfide type, has the highest conductivity, and Japan’s decades-deep players (Toyota, Idemitsu) are built around it. But it reacts with trace moisture to release H₂S, so it needs extremely strict dry-room control — a serious manufacturing-cost barrier, not a physics one.
The halide type is the development to watch. In July, Sumitomo Chemical announced it will mass-produce a halide electrolyte that — it says — matches sulfide conductivity while running on existing lithium-ion production lines. That prioritizes manufacturability over the spec sheet.
One issue I had hoped you might address is how the ions migrate through a solid electrolyte (as opposed to the liquid case where mobility of dissolved material is not a problem).
I was curious too, but a brief overview is provided in footnote 2.
I'd never really registered that a gas car gets its oxidizer for free from the air while a battery has to carry its own. That framing explains the energy density gap better than any spec sheet: solid-state trims the scaffolding, but the cathode you have to haul around isn't going anywhere.
Your application of the virial theorem seems wrong. Batteries are presumably not in equilibrium when (dis)charging, and they're more than 50% efficient.
I've seen Indian software engineers in battery-adjacent fields over-invest in RSUs of solid-state battery startups, assuming commercialization will mirror the hype timeline.
CATL's 4/9 readiness suggests a 5-10 year horizon at least — long enough that relying on it for near-term retirement growth is risky.
The pattern: treat it as a speculative allocation, not a core holding. Run the numbers on a 10-year delay.