My understanding of IATA rules are that Li-Ion batteries with more than 100Wh of capacity [(mAh)*(V) = (Wh)], can only be "carried-on" passenger planes with exceptional airline approval. This is because they need to quantify the total number of UN3171 and UN3481 batteries already booked in the cabin and/or in cargo, outside of the 100 laptops and 150 cell phones that would normally be there. This is also why you can't just buy a $400 ebike on Alibaba, and ship it air freight from Guanzong...that sucker has to be boxed up LCL and ocean shipped as dangerous goods, and the extra hassles are reflected on the landed tag.
Until newer and better non-lithium capacitation becomes commercially available, the options are limited. Thankfully there is a whole industry of people working on the next wave of post lithium-ion tech.