I had the same thought reading the article, but after some thought, I doubt it.

Grid transmission can be as low as 0.5% per 100 miles already. Batteries lose about 10% of the energy by storing it, that leaves you with needing to go at least 2000 miles in order to make up the battery loss difference, plus needing the energy to move the batteries physically.

Batteries are cheap to charge in-place. Once you load those into a train you have to add the cost (both economic and in energy conversion rates) of moving the whole mass around in a diesel powered vehicle.

We already do that with alkaline batteries, and we pay premium price per BTU because of the convenience of begin able to carry small quantities of electricity around. But if you want to move city-powering amounts of it (think millions of Megawatt-hour), I am guessing a grid is more efficient.