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ElephantsAreHeavy t1_is0t1go wrote

How can a battery be anode-free... there are two essential parts on a battery, the anode and the kathode. Missing one of them, is like having a magnetic monopole, it would be a nobel prize worthy discovery.

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SGTLuxembourg t1_is1f7y3 wrote

It’s bad branding but essentially a lithium anode would be a metal film on a copper foil. As you charge the battery Li from the cathode would plate in the existing lithium which acts as a reservoir to compensate for any lost capacity due to natural aging. In an anode free configuration there is zero initial lithium, just bare copper (maybe with a coating or some other modification but the key detail is zero initial lithium on the anode. That is the primary source of gravimetric capacity increases in “anode free” cells since you can remove the weight of the lithium reservoir. This requires extremely high coulombic efficiency since there is nothing to compensate for any lost lithium.

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ElephantsAreHeavy t1_is1lft1 wrote

A lithium-free anode is someting completely different from a anode-free battery.

I just wanted to point out the ridiculousness of what is written. You are absolutely correct in the explanation, but their wording is still wrong.

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SGTLuxembourg t1_is28wns wrote

Yeah definitely, in the research community I am a part of we try to say “lithium-free” rather than anode-free but the later is more common in the literature. Even then it isn’t lithium free always just at assembly (and theoretically at 100% discharge if everything is behaving ideally).

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Luniusem t1_is27ujw wrote

Anode-less architectures have been around for a while, it basically just means that the anode is formed in-situ during charge, but the as built battery only has a current collector onto/into which the anodic active material will go, as opposed to having an active material anode already present in the uncharged state.

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funkysnave t1_is2z25u wrote

Isn't that just what is referred to as a half-cell in most literature?

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Luniusem t1_is3isxc wrote

Different concepts, half-cell means your only testing half the cell, usually by means of an experimental setup where the opposite electrode is not limiting, either by just using a surplus of active material or using some standard electrode that doesn't correspond to your proposed chemistry. You can't really physically run a half cell, rather, it refers to a test setup where only one electrode is really being tested. Anode-less designs have a fully active anode once they are at non zero state of charge, they just don't have active material on the "anode" as built. Metal plating batteries are often built like this, were you just have a current collector of some other material, and the cell only goes to it's theoretical potential once you start depositing the anodic material on the current collector.

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