Why most (or all?) batteries can be discharged at an higher C rating than the charging C rating?
For example I have the following battery for my quad-copter: https://hobbyking.com/en_us/turnigy-4000mah-3s-30c-lipo-pack.html
If you look at the specs tabs, you will see that the C rating for Discharge is 30C which means I can draw at max 120 AMPS continuously (which will last me about 2 minutes) and the C rating for Charging is 2C, which means I can charge it at 8 AMPS continuously (which will take about half an hour to charge fully). All of the Lithium based batteries I found has significantly higher C rating for discharge than for charge.
What is the reason for this big difference? Is it limited to Lithium based batteries only or is it a common trend across most types of batteries?