According to a report in Japan’s Nihon Keizai Shimbun, Sony is researching new battery technology for mobile devices that promises up to 40 percent longer battery life. This lithium-sulfur battery technology apparently offers both greater energy capacity than conventional lithium-ion batteries and significant weight savings. However, as the Wikipedia article on this battery type says, “as of early 2014 none were commercially available.”
The Nikkei report emphasizes that Sony has only something like 10 percent of the mobile phone market, and may be looking at such innovations to boost its market share. That said, given some of the other new technologies on the horizon, such as powered paper, you really have to wonder whether a 40 percent power storage density increase is enough. Or if Sony can ever regain the innovation edge that it had in the Walkman era. Or that led to the rollout of the Sony Reader line of e-book readers with the debut of the Sony Librie in 2004, supposedly the first commercially available E Ink ereader. Sony wasn’t able to hold on to that innovation edge, and as of 2014 announced that it was withdrawing from the ereader market. So it doesn’t seem like there’s any sense waiting for a longer-lasting ereader from Sony.