Coin-shaped lithium secondary battery and IoT device
摘要
說明書
The green sheet containing the lithium complex oxide (e.g., LiCoO2 green sheet) and the green sheet containing the excess-lithium source (e.g., Li2CO3 green sheet), if desired, are sequentially disposed on a bottom setter, and a top setter is disposed on the green sheets. The top and bottom setters are made of ceramic, preferably zirconia or magnesia. If the setters are made of magnesia, the pores tend to get smaller. The top setter may have a porous structure, a honeycomb structure, or a dense structure. If the top setter has a dense structure, the pores in the sintered plate readily get smaller, and the number of pores tends to get larger. As necessary, the green sheet containing the excess-lithium source is preferably cut into a size, 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.
After the green sheet containing the lithium complex oxide (e.g., a LiCoO2 green sheet) is placed on the bottom setter, the green sheet may be optionally degreased and then calcined at 600 to 850° C. for 1 to 10 hours. In this step, the green sheet containing the excess-lithium source (e.g., a Li2CO3 green sheet) and the top setter may be sequentially disposed on the resultant calcined plate.
