Ann: SOR Self-charging Battery Ink Successful Scale Up, page-11

A couple points. The drones won't need to land, they just carry two batteries and switch.
Second point, on the transporting dangerous goods, the point was the lithium batteries have inherent risk when being transported on planes due to their propensity to explode. These do not.
I'm actually hoping they stick these into some sort of mining machines to dig up their gold/meteorite play. Imagine the cost saving if you had an autonomous machine doing the mining that could recharge on the fly underground. The restrictions currently in the industry of going to certain depths due to cost/temperature could be broken.