Hvorfor blåser lipo pakkene seg opp og hva er akseptabelt??

[thomas.kjolstad]

Hvorfor blåser lipo pakkene seg opp og hva er akseptabelt??

[Quadrocopter]

Her er en meget god forklaring fra en som har studert sakene

In a nutshell, the lithium batteries have 3 components which make them work.
A cathode, made out of either lithium, manganese, and oxygen, or lithium, cobalt, and oxygen, an anode made out of lithium and carbon held in a semi-liquid state, and a separator between the two made of a special polymer soaked with a conductive electrolyte.
A chemical reaction between the cathode, anode, and electrolyte causes electrons to flow, giving us electricity.

The typical cause of puffiness is either age, or abuse (or a combo of the two.) As the cells are used, the anode naturally degrades, producing oxygen and leaving the Lithium and other element in a useless state.
In addition, as usage goes along, the cathode slowly starts to produce metallic lithium.
The oxygen produced by the anode bonds to the metallic lithium produced by the cathode, again limiting cell usability, and creating lithium "rust."
However, the anode produces oxygen faster then the cathode produces metallic lithium for it to bond to.
This means that the oxygen has nowhere to go, and pressurizes the cell, making it puff out.
This is also one of the reasons an overcharged cell will ignite under water without the presence of oxygen and air. Also due to lithium being HIGHLY reactive with water.

New question, how come a cell that has puffed slightly, can de-puff (scientific term for sure) when its properly charged again. (to a point... I know thats not true under heightened circumstances)

This I have no idea, but possibly because the anode is recovering some of the oxygen and re-creating it's original chemical makeup. OR under the heat and load of charging, the cathode is absorbing more oxygen, turning into lithium oxide (rusted.) I think the former explanation is probably the better solution.

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[thomas.kjolstad]

Hvorfor blåser lipo pakkene seg opp og hva er akseptabelt??

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