Power Plug: XT60, Size: About 36*40*110(MM), Constant Discharge: 70C, Approx Weight: 380g, Item Name: 2200mah 70C 22.2V 6S1P Lipo Battery, Cells: 6S (22.2V), Capacity: 2200mAh.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Updated:
Banggood
Warehouse in China.
Link: Infinity 22.2V 6S1P 2200mah 70C RC Battery
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons:
1. First page
2. Second page
Price history and price alert
Do you need price history chart (for all/most countries) for Infinity 22.2V 6S1P 2200mah 70C RC Battery? There we go. The lowest price was: $35.62.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).