It is a Lithium Ion (Li-Ion) Polymer type battery.
It should have the Voltage, Current rating and dimensions information printed on the battery itself.
Unfortunately the ifixit repair guide for the battery removal for the camera does not show the specifications clearly.
It may say something, (and this is only an example) such as 3.7V 250mAH 502030.
The 502030 is a format convention used to describe battery dimensioning. It means that the battery is 5.0mm thick x 20mm long x 30 mm wide. The first 2 digits are always the thickness (or depth) of the battery (note the decimal point is used. It is not used for length and width), the next 2 are the length, and the last 2 are the width. Obviously sometimes when the length or width exceeds 100mm it will be 3 digits etc
You would need to open the camera and view what is printed on the battery and then use the information to search such sites as Ebay, Alibaba etc to find suppliers of the part. If you cannot find an exact replacement, as long as you get the Voltage (V) and Current (I) values correct and the battery will physically fit into the camera you may find a battery that is physically slightly smaller but has the same V/I characteristics (or even close as far as the Current goes) that will suffice. Ensure however that the Voltage specification (whatever it is) is exactly the same
Hopefully this is of some help