You’re thinking of lead-acid batteries. The various types of lithium ion batteries are considerably lighter and more compact. The Tesla automotive battery pack is very thin and serves as the floorboard of their vehicles, sort of like a skateboard and the chassis is nicknamed a skateboard in fact.
http://enipedia.tudelft.nl/wiki/Tesla_Model_S_Battery
140 WHr = 478 btu
https://www.google.com/search?q=convert+watt+hour+to+btu&rlz=1C1VFKB___US753US753&oq=convert+watt+hour+to+&aqs=chrome.5.0j69i57j0l4.10875j0j7&sourceid=chrome&ie=UTF-8
Energy content jet fuel: 18,800 btu/lb
https://hypertextbook.com/facts/2003/EvelynGofman.shtml
Convert 18,800 btu/lb to btu/kg = 41,446 btu/kg
https://www.google.com/search?q=convert+btu%2Flb+to+btu%2Fkg&rlz=1C1VFKB___US753US753&oq=convert+btu%2Flb+to+btu%2Fkg&aqs=chrome..69i57j6.10135j0j4&sourceid=chrome&ie=UTF-8
Compare: 478 btu/kg for Tesla battery vs 18,800 btu/kg for jet fuel.
Conclusion: It's more likely to see stokers shoveling coal in an airliner, than there is to be a battery powered airliner.
Battery technology was pretty much stagnant for almost the entire 20th century. However, tremendous strides have been made in the last 2 decades, thanks to the demands of laptop and cell phone users. I used to believe that batteries would never reach the point where they would be practical in an applications like this. Today, I believe it is just a matter of time. Conservatives need to embrace this reality or risk being seen as flat-earthers.