The EV battery maker of the moment is, well, having a moment.QuantumScape (QS 11.33%) stock doesn't look like much of a bargain at first glance. After all, it's zoomed nearly 140% in price this year. That's over 10 times the percentage rate increase of the benchmark S&P 500 index. Yikes!But there are very good reasons for the rally, and I think QuantumScape remains a buy thanks to a future that could be -- pardon the expression -- very electric. Read on for more.The people's battery?For the uninitiated, Qua ...