I'm working on T-Nb2O5 films with a view toward electrochemistry. In theoretical literature, it was reported that there was the Li+ intercalation into the T-Nb2O5, which shows the electron transfer reaction. And it was reported that the lower the scan rate (or sweep rate mV/s), the more clearly the anodic/cathodic peaks could be observed.

However, in my case, when the CV run at the scan rate, I can't see the peak. Why did I only see the anodic/cathodic peak at the high scan rate? Typically, many studies used very low scan rates (e.g. 0.1 mV/s and they still had a peak in CV)

Here are the photos of the CV of 1 sample. There is no peak if I set the scan rate below 1000 mV/s. If the scan rate is above 1000 mV/s, the peaks appear.

I don't understand why it's acting like this. Please help me figure out this. Thank you!