Cathode including sintered polycrystalline material, secondary battery including the cathode, and method of manufacturing the cathode

A secondary battery comprising:

• an anode collector layer;
• an anode active material layer on a surface of the anode collector layer;
• a cathode collector layer;
• and
• a cathode active material layer on a surface of the cathode collector layer,
• wherein the cathode active material layer comprises a polycrystalline material having a plurality of crystal grains of a lithium-based oxide, and
• wherein the plurality of crystal grains are substantially oriented such that an angle between a direction perpendicular to a surface of the cathode collector layer and a direction of a lithium plane defined by lithium elements arranged in layers in the plurality of crystal grains is within about ±45°.