I’m going to deviate from the series I began with my last post to address the timely topic of battery safety. I’ll return to why it’s taking so long to build a better battery next week.
Last week Consumer Reports published an online article about Samsung Note 7 smartphones catching fire while charging. Over the Labor Day weekend, major media, including The Wall Street Journal, reported that “Samsung Electronics is recalling about 2.5 million Galaxy Note 7 devices, in a massive recall that analysts predict could cost the company about KRW 1 trillion ($904 million).” The article noted that, “…a flaw in the [lithium-ion] battery cell resulted in negative and positive electrodes coming together which is abnormal, causing the phones to be recalled.”
Other media, including BBC News, The New York Times, US News and World Report, USA Today and WIRED, broadened their coverage to include other lithium-ion (Li-ion) battery mishaps, causes and warnings. Examples include:
[The Li-ion battery is] why the Note 7 went haywire, why hoverboards have always been a dangerous investment, why Boeing had to keep the 787 on the tarmac, and why every few months there seems to be another report of a smartphone or laptop going boom. – WIRED
…lithium-ion batteries store a lot of energy in a tiny space, with combustible components separated by ultra-thin walls. If something happens to those separators, a chemical reaction can quickly escalate out of control. – US News and World Report
One expert urged the industry to find safer alternatives to lithium. “I think one should be concerned and push towards safer battery tech,” said energy storage expert Professor Clare Grey from Cambridge University. “That should be an important focus on research and industry development.” – BBC News
There are several ways a battery can become thermally unstable and explode or catch fire, but the root cause is most often linked directly to conventional Li-ion battery design and production. In an earlier blog post, LI-ION BATTERY DISADVANTAGES: Legacy of Magnetic Tape Production, I described how Sony’s decision to produce the Li-ion battery in the same manner as magnetic audio tape has produced serious side effects in performance and safety. Basically, conventional Li-ion design and production creates inherent friction between the goals of increasing energy density and improving safety. As one battery expert put it, “…when you improve one aspect, you compromise other aspects.”
The Enovix approach to battery design and production is radically different than that initially pioneered by Sony a quarter-century ago and still used to produce commercial Li-ion batteries today. Our modern 3D Silicon Lithium-ion battery platform decouples design, materials and production, which enables greater innovation in both performance and safety.
Our patented 3D architecture improves spatial efficiency and enables a 100% silicon anode to significantly increase Li-ion battery energy density. Combined with a modern photolithographic and wafer production process, it also provides several safety features not obtainable with a conventional Li-ion battery structure. These features are illustrated and described in a previous blog post, 3D CELL ADVANTAGE No. 2: Reduced Risk of Thermal Runaway. Collectively, these features reduce the danger of thermal runaway, thereby improving battery safety.
There are some who think that the Li-ion battery is near the end of its lifecycle, and that only a major change in chemistry will improve battery performance and safety. At Enovix, we believe that the Li-ion battery has much greater potential that can be liberated through improved design, materials and production. We see a mobile future powered by our 3D Silicon Lithium-ion Battery, which will deliver significantly greater energy density and much improved safety.