TDK claims solid state battery breakthrough

Context about TDK and the announcement

• Commenters note TDK is a long-established electronics company (cassettes, optical media, pro audio gear, components), now almost entirely B2B.
• The “Apple supplier” framing is seen as clickbait that oversimplifies TDK’s history and stature.

Energy density & what “100x” means

• The 1,000 Wh/L figure is ~100x TDK’s previous solid‑state coin cell, not 100x lithium‑ion in general.
• Estimates from the thread put this at roughly 2x current Li‑ion volumetric energy density (typical 250–700 Wh/L).
• No gravimetric (Wh/kg) data is provided; several commenters infer that if it were outstanding, TDK would highlight it.

Form factor, use cases, and limits

• The current tech is coin‑cell scale with specs like ~1.5V, ~100µAh, low discharge currents.
• Targeted uses: wearables, hearing aids, wireless earphones, RTC backup, tiny IoT/BLE devices.
• TDK itself says the ceramic structure becomes too fragile at larger sizes; scaling to phones, EVs, or cars is “not in the foreseeable future.”
• Some hope that even modest size growth over years could be transformative, but this is speculative.

Comparisons & implications

• Compared to gasoline (~9,500 Wh/L), this is still only ~10% by volume; but EVs are more efficient than ICE, so practical gap is smaller.
• A 2x density gain for mainstream Li‑ion or EV cells would be viewed as game‑changing, but this TDK cell is not positioned there yet.
• Coin‑cell improvements could dramatically improve smartwatch and earbud runtimes, or shrink devices at similar runtime.

Safety and reliability

• Solid‑state is seen as safer (no flammable liquid electrolyte, less bulging), though dendrite‑induced shorts remain a concern.
• Long‑life, non‑flammable coin cells are attractive for body‑worn devices and long‑term backups.

Skepticism, hype, and “battery breakthrough” fatigue

• Many express fatigue with frequent “breakthrough” press releases that never scale.
• Some are cautiously optimistic because this comes from an established manufacturer targeting commercial sampling and eventual mass production.
• Overall sentiment: promising incremental advance for small devices, not a world‑changing battery revolution.