Lithium-ion batteries store a lot of energy in a small space, making them the energy source of choice for mobile electronic devices. Today, mobile phones, laptops, e-bikes and electric cars are all powered by such batteries. Researchers at ETH Zurich have now developed a type of battery that, unlike conventional ones, consists entirely of solid chemical compounds and is non-flammable.Conventional lithium-ion batteries are not without their dangers: mobile phone batteries have exploded several times in the past, resulting in injuries, and only six months ago an entire row of houses burned down in the old town of Steckborn on Lake Constance. The blaze was caused by a model-making battery that allegedly caught fire due to being charged improperly.