[L473ncy]

Supposedly active braking is hard on the motor or something like that (was it something about overheating maybe?) but I'd use a weaker battery (if you're keen on using LiPo then 7.2V should do the trick, otherwise a 8.4V NiMh/NiCd will do the trick).

However yes a MOSFET with active braking (such as the TriggerMaster) will do the trick. Or maybe a 6.6V LiFePo4 (Lithium Ferrite Phosphor I think the proper name is). Note that the nominal voltage is 3.3V so either you get it in 6.6V or 9.9V flavours, also it's supposedly a "safer" alternative to LiPo which are prone to "exploding" (but that is if you abuse it and don't take care of it) But still it's probably a good idea to charge LFP batteries in a non flammable "battery bag" like most RC'ers do.