Apart from conductivity of current collectors, what is the other property that can have impact on Battery performance and how? Thanks in advance
Importent issue is also the chemical and electrochemical stability of the collectors. Cu is dissolving at the operating potentials of the cathodes, therefore it can not be used.
Al on the other hand is not stable in the voltage range of the anodes.
I agree with Lidiya. Critical point is in the metal's stability under polarization. Also important point: copper do not forming alloys with Lithium. And Al used us cahode current collector is protected by cathode active material.
If you wanna to use the same current collectors for cathode and anode you can use stainless steel foil ( it must be stable in range 0 V - 5 V from Lithiom reference electrode.
I agree with those comments, if you want to use same current collect for both electrodes, you can use Al for LTO based anode combinations. This certainly increase the energy density of the system compared to stainless steel based collectors.
Unfortunately, Al will form alloy with Li at lower potentials (
Cu and Li do alloy at a certain temperature indeed..
Klemm, W.; Volavšek, B., Z. Anorg. Allg. Chem. 1958, 296, 184.
To be in safe side you can use Ti current collector stable from 0V to 5V for Li
Furthermore, many electrolytes (especially containing LiPF6) form a passivation layer of AlF3 on blank Al minimizing the contact area between the electrolyte and the cathode current collector.
Current collectors are selected according to their electrochemical stability window. Cu current collector is stable at lower potential upto 3 V, while it start oxidizing if the electrode potential (or half cell potential) crosses 3.2 V vs. Li/Li+. So, the stable electrochemical window of Cu current collector is 0-3 V vs. Li/Li+ in case of LiPF6 electrolyte.
On the other hand Al is stable at high potential but it can react with Li at lower potential. Al is known to be reactive against Li through alloying reaction at an potential of ~0.6 V vs. Li/Li+. So, Al can be used as current collector for any electrode which works above 1.0 V like LTO.
A details about the stability and reactivate of the current collector can be found from the following paper
http://pubs.rsc.org/en/content/articlelanding/2011/jm/c0jm04353b#!divAbstract
If only one metal for current collector, then one of hard-stainless steels.
Copper is not alloying with lithium and it is therefore stable at low potentials vs. Li+/Li. It will corrode at high potentials. Aluminium is stable to corrosion at high potentials. Aluminium is alloying with lithium at low potentials and therefore useless for the negative electrode. So far there is no quality of stainless steel with is stable enough towards corrosion in a lithium battery. Ionannis Samaras is wrong in his statement.
Dear K. Edström,
what is your best proposal for (cathode) current collector in lithium ion batteries?
Dear K. Edström,
of course, most of us use Aluminium.
However, from the analytical chemistry view point, are you sure that Al do not ingest (even a small amount of) Li from the cathode electrode ?
Again the best one is Titanium current collector no corrosion detected until 4.8V-4.9V. all the rest like stainless steel, Ni, Fe, etc... will suffer corrosion.
Aluminum is usually used despite some corrosion problems reported for materials cycled higher than the stability of the electrolyte.
Kristina, I was also like you believing that Li cannot react and alloy with Cu but in certain condition (not in the case of the current collector). But nano Cu can alloy a tiny bit with Li!
You can find a bit more in this article, I was really surprised!
Klemm, W.; Volavšek, B., Z. Anorg. Allg. Chem. 1958, 296, 184.
Al is best for cathodes, though it corrodes on initial cycles, the passivation layer formed on Al (Al-PF6 like species) prevent from further corrosion and resulting in long cycling stability
There are few reports on Cu current collectors reactivity with Li, as we don't have alternative stable current collectors at lower potentials, copper is using in all commercial batteries
Potential Difference between the cathode and anode is quite important. if you use the same current collector , it might produce the short-circuit and damage the electrochemical operations
Do we have different types of current collectors like stiff or ductile used in lithium ion battery?
1. We are planning to use copper as current collector in the anode which is lithium metal and electrolyte salt is LiTFSI. Please can you suggest what will be the stable potential window of copper with LiTFSI.
2. What is the Standard Sulfur reduction potential.
- Badges
- Science topic