Toma Stankulov yes this is anode materials, but why there is no reductive peaks one second cycle onward, that's mean there is no reversibility in reduction of active materials? or this first cycle peak is only showed SEI formation?

Thanks for your answer

As Toma Stankulov states, it looks indicative of an initial solid-electrolyte interface (SEI) formation process. Can you provide any further information on your experimental setup?

You may find the following article interesting:

https://pubs.rsc.org/en/content/articlelanding/2012/cp/c2cp40595d#!divAbstract

On a different note, I respect your patience: multiple scans from 0 to 3.0 V at 0.1 mV.s-1!

Jules.

It is metal oxide based anode material,normally such narrow peaks must gave reversible response, and if it is SEI layer indication, then why two peaks? The other reductive peak should be of redox reaction, which seems not reversible

Go To this Link:

https://en.wikipedia.org/wiki/Cyclic_voltammetry