Kai And Hyundai are looking to put batteries into the structural components of EVs which would potentially increase range significantly but might reduce repairability. This repairability problem can be mitigated in any one of three non-exclusive ways.
Something seems missing from the description. What would make the most sense with the articles description is if there were two packs each with different chemistries. One cheap and low density, such as NA-Ion (Sodium-Ion) that could take care of 90% of EV driving needs for trips under, say, 100 miles. The second pack being a much higher density chemistry like NMC (Nickel, Manganese, Cobalt) which could add significantly more range for the same cubic cm of volume in the vehicle, but the battery would have far fewer cycles compared to other chemistries.
The idea being, beat the heck out of the Sodium Ion battery and make it easily serviceable/replaceable at the cost of range for the same volume consumed, while the NMC battery would be gently cared for and only called on in the more extreme demands of range.
If that’s what the author was trying to say, it was not clear.