The encyclopedia · Engineering & Operations · Technical decision · 1981-1991
Akira Yoshino tamed dendrite-prone lithium by hiding it in a carbon anode
Yoshino paired a carbon anode with a LiCoO2 cathode so lithium ions shuttle in and out, giving a safe rechargeable battery.
Asahi Kasei
the move
In 1981 Akira Yoshino at Asahi Kasei began working on a rechargeable battery around a material others had dismissed. He started from polyacetylene, then moved to carbon, which could host lithium ions inside its layers.
His construction was a negative electrode made of carbon and a positive electrode of LiCoO2. Because the lithium never exists as bare metal — it stays intercalated in the carbon and the cathode — the dendrites that ruined metallic-lithium cells are impossible.
He filed the patent for a non-aqueous secondary battery with this combination in 1985, and in 1986 he ran the world's first safety tests on the system.
why it works
- Carbon hosts lithium ions without them plating out as dangerous metal.
- Two different intercalation electrodes give a stable voltage that holds over many cycles.
- No metallic lithium means no dendrites, so the battery is both rechargeable and safe.
what transfers
The dangerous reagent is not the only option — store it inside a host lattice. Intercalation trades fast, risky chemistry for safe, rechargeable storage.
what came after
Sony launched the world's first commercial lithium-ion battery in 1991, and the chemistry that Yoshino invented became the standard for the portable-electronics age. He shared the 2019 Nobel Prize in Chemistry for the work.
references
- Dr. Akira Yoshino chosen for the Nobel Prize in Chemistry
- How chemistry Nobelist Akira Yoshino bucked conventional wisdom to develop the lithium-ion battery
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