Since none of these products are available yet, it’s hard to know whether they'll live up to the hype. Experts say battery life is getting better in consumer electronics—through a combination of super-efficient processors, low-power states, and a little help from advanced technologies like silicon anode. It’s just not necessarily getting 10 times better. Conventional lithium-ion batteries have their energy density limits, and they typically improve by single-digit percentages each year. And there are downsides to pushing the limits of energy density.“Batteries are getting a little bit better, but when batteries get better in energy density, there’s usually a trade-off with cycle life,” says Venkat Srinivasan, who researches energy storage and is the director of the Argonne Collaborative Center for Energy Storage Science. “If you go to the big consumer electronics companies, they’ll have a metric they want to achieve, like we need the battery to last for 500 cycles over two or three years. But some of the smaller companies might opt for longer run times, and live with the fact that the product might not last two years.”Srinivasan, like many other technologists these days, is optimistic that relatively new developments in silicon-anode technology will improve battery life. (One of the companies Srinivasan advises, called Enovix, has developed a cell architecture for silicon-anode batteries that it believes will set it apart from others in the market.) Conventional graphite-based lithium-ion batteries are rechargeable batteries in which lithium ions move from the negative electrode (anode) to the positive electrode (cathode). A key component of these batteries is graphite, which goes in the anode and is highly conductive. In silicon-anode batteries, silicon nanoparticles replace some or all of the graphite in the anode. This silicon can, in theory, absorb more lithium than graphite, which equates to more energy density; it’s also prone to swelling and even fracturing.