Recently, in Japan, Toyota unveiled a prototype battery that uses a ceramic coating on the positive electrode materials to overcome a problem that has plagued solid-state batteries: material produced in the chemical reaction between the boundary surfaces of positive electrodes and solid electrolyte increases cell resistance. Overcoming this hurdle moves solid-state batteries one step closer to production.
Tech On attended the unveiling in Japan and described the makeup of Toyota's prototype battery like this:
Toyota also confirmed that the prototyped battery can be safely used at temperatures above 212 Fahrenheit, a level that would cause the liquid electrolytes in existing li-ion batteries to boil over.Four sets of positive electrode layers, solid electrolyte layers and negative electrode layers are laminated, and the average voltage of the cell is 14.4V (3.6V x 4). The laminated cell measures about 10 centimeters square. Toyota exhibited the cell right after it was charged and it output a voltage of 16.26V (4.065V per layer). The positive electrode, negative electrode and solid electrolyte of the prototyped cell are made by using lithium cobalt dioxide (LiCoO2), graphite and sulfide, respectively.
[Source: Tech On]