Crack-free lithium ion injection into alkali silicate glass using Li+ conducting microelectrodes

The crack-free lithium ion injection into alkali silicate glass below the glass transition temperature, which is difficult by conventional ion exchange using a molten salt, was achieved by means of the solid state electrochemical technique using Li+ conducting microelectrodes. The fundamental doping system consists of an anode/LiLaSiO4 microelectrode/glass/Na–β″–Al2O3/cathode system, where the Li+ in LiLaSiO4 is injected into the glass under an applied electric field, then the Na+ in the glass was eliminated from the glass to Na–β″–Al2O3. As expected, the crack development strongly depended on the applied voltage, and was suppressed under a lower voltage. Furthermore, it was confirmed that the post annealing after doping is also effective for fabrication of a crack-free doped glass. The breaking mechanism of the glass was mainly discussed by the distinction of the ionic radius between the dopant and mobile cation in the glass.