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​Rollable Mobile Products Need Flexible Batteries
March 04, 2019
 
When UDC started, 20 years ago, Janice Mahon, VP of Marketing showed a concept of a notebook with a rollable form factor. While LG’s rollable TV can be supplied with electricity from a wall outlet, a cell phone or a notebook must be powered by an internal battery, so that seems to be the constraining issue. Lithium-Ion (Li-Ion) batteries are widely used in portable electronics, especially mobile phones. Li-Ion batteries are efficient and have high energy density. However, they are also notorious for occasional battery explosions. The Samsung Galaxy Note 7 could not be carried on planes because of this problem. Because of this and related problems, the Electrical Appliances and Consumer Products Safety Rules of Enforcement were amended last year. These rules specify two certification systems. One is "safety assurance" and the other is "safety certification". Before the amendment last year, Li-ion batteries could be distributed after manufacturers reported they had the assurance of the testing agency that had conducted tests in accordance with the relevant safety standard (KC 61233). 

Now, the safety certification requires inspections of the factory where the batteries are produced in addition to product testing by the safety certification agency. The rule is being criticized for its narrow scope in mandating that only Li-ion batteries with an energy density over 700 Wh/L be submitted for testing, while most smartphone batteries fall under that threshold. Moreover, Li-ion is especially dangerous compared to other types of batteries, and so surely high standards of safety are required, as well as a being hard and non-flexible. Will mobile products be adopted to use a rollable form factor?  Because of the high safety requirements of Li-ion batteries, it is unlikely in the short term. In contrast to rapid technological growth, battery technology growth has been quite slow. True wireless charging without having to place the device on a platform has been promised for years, but there are no commercial installations, as yet and the promise of flexible batteries using graphene’s single atom carbons is still an R&D project. I guess that Janice (now DuFour) will have to wait a while to see her dream concept come true.
 
Figure 1: Rollable Mobile Notebook

Source: UDC