Hybridization can be a good thing (For example, the McLaren P1) but it comes with a number of down-sides. batteries are heavy, which is bad for performance, batteries require a lot of carbon emissions to manufacture, which kinda defeats the purpose, and batteries are filled with all sorts of environmentally dangerous chemicals, which also defeat the purpose.
This is why we drooled over Toyota's Hybrid R concept that used supercapacitors instead of batteries. Not only is the supercapacitor more environmentally friendly, but it also can discharge energy faster, making it better for motorsport.
Now Volvo has created a way to put supercapacitors into the body panels of a car, sandwiched between two layers of carbon fiber, and we think that's awesome. Of course, carbon fiber costs an arm and three legs, so we're not holding our breath to see two layers of it on a Volvo any time soon.