Smart Battery Tells You When It's About To Explode

sciencehabit writes Material scientists have found a clever way to alert users of damaged batteries before any hazard occurs. A typical lithium-ion cell consists of a lithium oxide cathode and a graphite anode, separated by a thin, porous polymer sheet that allows ions to travel between the electrodes. When the cell is overcharged, microscopic chains of lithium, called "dendrites," sprout from the anode and pierce through the polymer separator until they touch the cathode. An electrical current passing through the dendrites to the cathode can short-circuit the cell, which causes overheating and, in some cases, fire. Attempts to stop dendrite formation have met with limited success, so the researchers tried something different. They built a "smart" separator by sandwiching a 50-nanometer thin copper layer between two polymer sheets and connecting the copper layer to a third electrode for voltage measurement. When the dendrites reach the separator, the voltage between the anode and the copper layer drops to zero, alerting users that they should change the damaged battery while it is still operating safely—disaster averted.

Comments

Sounds like a good idea

[willoughby]

Alerting the user to change the damaged battery makes sense. Now we need to convince the manufacturers to design devices which would make this possible.

Re:How about a battery that doesn't explode?

[sjames]

I was wondering the same. If the battery can warn that it is about to be compromised to explode, it should also be able to disconnect itself and slowly discharge through a resistor so that it doesn't explode. Many LiIon batteries already have an IC at one end that disconnects it when it is overdischarged or if the discharge rate is too high. If they want to get fancy, that slow discharge could be through a red LED to visibly indicate failure.