The solid-state battery maker still faces formidable challenges. QuantumScape (QS 5.69%), a maker of solid-state batteries for electric vehicles (EVs), initially attracted a stampede of bulls when it went public by merging with a special purpose acquisition company (SPAC) in November 2020. The combined company's stock opened at $24.80 and skyrocketed to its record high of$131.67 less than a month later. But today, QuantumScape's stock trades at about $5. The bulls retreated as the company struggled to comm ...