The safer design incorporates a heat-resistant insulator that would hopefully prevent short circuits, which can often lead to overheating, fires, and explosions. In addition, a more controlled process will ensure that the battery cells are not contaminated with electrically conductive particles, as Sony’s batteries were rumored to have been.
Seriously, though, how was this not a priority the first time around? I’d think that “product does not explode” would be pretty close to the top of the checklist for designers. Well, regardless, way to live up to your motto, Panasonic. Ideas for life, indeed.