There are experimental train engines with pantograph for mainlines and batteries for the "last mile" the issue is that for freight you often have heavy trains w

There are experimental train engines with pantograph for mainlines and batteries for the "last mile" the issue is that for freight you often have heavy trains which need lots of power, pulling the required batteries would need lots of power as well, not to mention charging times. More likely in the short term are electric engines, with a Diesel generator for the last mile (i.e. Bombardier TRAXX)