Lithium ion batteries get bendy with polymer gel

Scientists have developed a method for flexible lithium ion battery production that opens possibilities for batteries that can be bent into any manner of shaped device.

A method involving a novel polymer gel also means that lithium ion batteries can be created which are lower in cost, good news for laptops, mobile and tons of other devices.

The technology has been developed by Professor Ian Ward at the University of Leeds, and involves replacing the liquid electrolytes which are currently found in lithium battery cells.

Usually lithium ion battery cells are separated by a porous polymer film separator and liquid chemical filler.  This then allows the lithium ions to move between two electrodes, as well as stopping the electrodes from short-circuiting.

But with the development of the polymer gel the liquid electrolytes could be used instead.

As the gel can be made into a thin and flexible film this offers various benefits, such as allowing for a production process that is “fast, efficient and low cost”.

As well as the polymer gel removing the need for a separator, Professor Ward has patented the production process which holds the gel between a cathode and an anode.  This apparently creates a strip that is both highly conductive and merely a few nanometres thick.

Although the result looks like a solid film, the professor explains, it is actually mostly liquid electrolyte.  He likens it to the principle of making a jelly, but rather than hot water and gelatine it is a polymer and electrolyte mix.  Similarly the end result is solid but flexible.

The gel film can then be cut to any size, and due to the flexibility it can be bent to fit the geometry of many device designs.