which one is cathode material of the battery connectors
@Zhao-Jun Be careful please - your drawing is wrong.
The lower terminal - which is closer to the Expansion Header - is the negative terminal of the battery connector (ie. the "cathode" of the LiPo battery).
You can check it with an ohmmeter easily - this terminal is connected to the GND.
Yes, the battery symbol in the schematic is reversed, but this is just a schematic symbol and has no impact on the actual hardware.
BTW I don't have any Omega2 Pro board - the above is my "extrapolation" - because of the battery connector on the Power Dock is same.
Please correct me if I am wrong.