The court documents in question are those belonging in the case between Apple and A123 Systems in which the latter alleges that Apple had poached key employees from their company. For those unfamiliar, A123 Systems is a company that builds batteries and energy systems and according to the court documents, they claim that Apple had poached employees all of whom have experience in battery technology.
They go on to allege that these employees are now working at Apple in similar “if not identical” fields. The document also mentions A123’s former CTO who had previously helped develop batteries for Formula 1 racing cars. All of this seems to prove that Apple is at the very least interested in this battery technology.
Whether or not it will lead to the creation of an electric car remains to be seen, or maybe Apple has similar plans to that of Tesla and their Powerwall. Previously there were claims that Apple had a team of hundreds already in place but until we actually hear from Apple, take it with a grain of salt for now.