Flexible Batteries Enable Sensing Smart Labels
Batteries have not been a triumph of rapid innovation -from lead acid, nickel-cadmium, to nickel-metal-hydride and lithium-ion batteries, the development of batteries has significantly lagged many other components.
For example, lithium-ion batteries, which are the mostly successful commercial battery system nowadays, have only seen a 1.6 times improvement in energy density over the last 24 years. Not exactly a follower of Moore’s law like progress. It is already very optimistic to expect the energy density of lithium-ion battery to increase another 30% in five years time. Materials that can be chosen for the battery development are also limited. Companies see the challenge – and opportunity.One significant development has been flexible battery technologies. However, even though thin, flexible batteries have been available for over fifteen years they have had limited commercial success. That is not really a surprise: they have been more expensive, offer lower capacity and have a shorter shelf life than regular button cell or larger batteries.As a result, they have tried to exploit their thinness and flexibility as a way to differentiate – doing something that regular batteries cannot do. Successes have been found in a small number of niche applications, such as powered skin patches, where the battery provides a voltage across an area of skin, opening the pores and allowing the anti-wrinkle cosmetic on the patch to be absorbed about ten times more quickly versus non-powered patches, an effect known as iontophoresis. For a patch applied to a face, that product is only possible with an unobtrusive thin and flexible battery. It created a new product category and price point – here the flexible battery was not a value sell proposition but an enabling sell.