Why are the charge and discharge rate of Lihium Polymer Batteries different?
My best "educated guess" is that if you are discharging a battery, the "heating effect" is decreasing with time, whereas when you are charging the battery, the heating effect is increasing with time.  So, as time passes, nothing happens to the battery when discharging.  But in the second case, most likely the battery would explode, or at the very least, burn up!  This still can happen, even at the lower charging rate if the battery can't dissipate the heat generated at this current.