Coin-shaped lithium secondary battery and IoT device
摘要
說明書
Besides the above green sheet containing lithium complex oxide, another green sheet containing an excess-lithium source is then prepared, if desired. The excess-lithium source is preferably a lithium compound other than LiMO2. The components other than Li in the compound evaporate during firing. A preferred example of such a lithium compound (an excess-lithium source) is lithium carbonate. The excess-lithium source is preferably powder, and has a volume-based D50 particle diameter of preferably 0.1 to 20 μm, more preferably 0.3 to 10 μm. The lithium source powder is mixed with a dispersive medium and additives (e.g., a binder, a plasticizer, and a dispersant) to form a slurry. The resultant slurry is defoamed by stirring under reduced pressure, and the viscosity is preferably adjusted into 1000 to 20000 cP. The resultant slurry is formed into a green sheet containing an excess-lithium source. The resultant green sheet is also in a form of independent sheet. The sheet can be formed by any known process and is preferably formed by a doctor blade process. The thickness of the green sheet containing the excess-lithium source is appropriately selected, such that the molar ratio (Li/Co ratio) of the Li content in the green sheet containing the excess-lithium source to the Co content in the green sheet containing the lithium complex oxide is preferably 0.1 or more, more preferably 0.1 to 1.1.
(c) Lamination and Firing of Green Sheets
