Li6.4La2.8Al0.2Zr1.4Ta0.6O12 (LLZO) was synthesized via bulk ceramic processing methods. Li2CO3 (High purity chemicals JPN 4N), La2O3 (Alfa Aesar USA 4N), ZrO2 (1Micron) (Alfa Aesar USA 3N), Ta2O5 (0.5Micron) (High purity chemicals JPN 3N), and Al2O3 (TAMEI JPN 4N) were ball milled for 24 hours in ethyl alcohol, and then dried at 80°C for 24 hours. 10% by weight excess of Li2CO3 was used to compensate for lithium loss during calcination and sintering. The mixture was then calcined at 950°C for 10 hours, followed by attrition milling in isopropyl alcohol for 2 hours at 450 rpm. All milling used zirconia balls. The calcined and milled powder was then cold pressed uniaxially under 2 tons of force for 5 minutes. It was pressed into a tube shape with one end closed. The tube dimensions were 5 mm outside diameter, 3 mm inside diameter, and 2.5 cm long. After pressing, the tube was sintered at 1200°C for 4 hours. The tube was covered with the calcined powder to help to prevent lithium loss. The density of the sintered ceramic was measured to be 93%.