Lithium-ion batteries have lower energy density and have been a key component of portable electronic devices. Not just mobile phones and gadgets, even e-bikes and electric cars are now powered by such batteries.
But conventional lithium-ion batteries can also pose a safety hazard. There have been reports of phone batteries exploding under certain conditions, resulting in injuries.
Thanks to researchers at ETH Zurich, lithium-ion batteries now can be made entirely of solid materials that shall not be flammable.
It contains neither liquids nor gels, unlike conventional ones that is made up of solid chemical compounds. The battery will not ignite even at very high temperatures, giving it a safety advantage.
“Solid electrolyte has been used in the new battery and they can be operated at high temperatures. They can even be directly placed on silicon chips. These new batteries could revolutionize the energy supply of portable electronic devices,” said lead researcher Jennifer Rupp, Professor of Electrochemical Materials at ETH Zurich in Switzerland.
If a battery is improperly charged, overcharged or left in the sun, the liquid can ignite. In certain cases, the gel can swell up. This is not the case with solid-state batteries. In such types of batteries, both the electrodes and the intermediary electrolyte are made of solid material.
Batteries produced in this arrangement could theoretically operate at a normal ambient temperature. However, they work best at 95 degrees Celsius and above.
The key challenge in developing solid-state batteries is to connect the electrodes and electrolyte in such a way that the charges can circulate between them with less resistance as possible.
The ETH researchers have developed an improved electrode-electrolyte interface. A sandwich-like battery was constructed that features a layer of lithium containing compound (Lithium Garnet) that acts as a solid electrolyte between the two electrodes. It is one of the materials with the highest known conductivity for lithium-ions.
The research work has been reported in the journal Advanced Energy Materials.