There are some data sheet that will list and show which side it Negative and Positive for a battery. These are referred to as (+) and (-). However they also can list Anode and Cathode. Anode on the Negative side and Cathode on the Positive side.
This can be confusing as the Anode is Positive and Cathode is Negative.
This is basically referring to the flow of electricity.
When a Battery is being charged it is charged from Positive to Negative. This would mean positive is Anode and negative is Cathode.
When a battery is being used (discharged) the electricity will flow from the the positive terminal to the negative terminal. This will mean that the Positive is Cathode and Negative is Anode.