Is it possible to reload Electric Aircraft in mid-air from a tanker aircraft?
This would certainly be possible, but the current status (pun intended) of the battery technology makes it pretty much pointless.

The charging would simply take too long: for example, Eviation Alice has a battery capacity of 900kWh. If we were to charge, say, 75% of this (because you would need to have some reserve capacity in case charging does not work out) it would take about 10 hours to charge if the charge time was comparable to Tesla Superchager (85kWh battery charges in about 75minutes =1.13 kwh/minute). Even if the battery was charged in ten parallel segments, charging would still take an hour.

Alice has an endurance of about two hours, so to double that, you'd have to spend at least an hour, most probably more charging.

Then, there's of course the sillyness of charging an electric aircraft with electricity made from jet fuel (or diesel)... it would be far more efficient to use that fuel to propel the aircraft without the engine-alternator-charger-battery-motor -detour.

For further reading, please see this Aviation Stack Exchange question regarding aerial refueling, many of the points raised in the answers also apply to aerial recharge.