Volkswagen seems very interested in solid-state batteries that would significantly increase the range of electric cars and is suspected as an investor in start-up QuantumScape, which was founded in 2010 in California and focused on some breakthrough technology originally derived from Stanford University.
Unofficial reports claim that Volkswagen has bought a 5% share of the QuantumScape with an option for more.
In 2012, there was a ARPA-E grant at Stanford - The All-Electron Battery: A Quantum Leap Forward in Energy Storage,
"Stanford is developing an all-electron battery that would create a completely new class of energy storage devices for EVs. Stanford's all-electron battery stores energy by moving electrons rather than ions. Electrons are lighter and faster than the ion charge carriers in conventional Li-Ion batteries. Stanford's all-electron battery also uses an advanced structural design that separates critical battery functions, which increases both the life of the battery and the amount of energy it can store. The battery could be charged 1000s of times without showing a significant drop in performance."
It's possible that QuantumScape in stealth mode continues to work on some typeof breakthrough battery and Volkswagen sees the potential.
Reading some descriptions on the project, we wonder if this is too good to be true- "ultra-high energy and power densities, while enabling extremely high cycle life". We don't know the timeframe for developments, or any price indications and Volkswagen has yet to release a comment on the investment.
By the way, on the graph we see Barium Titanate and immediately EEstor springs to mind (oh yeah...).