| 摘要 |
PROBLEM TO BE SOLVED: To substantially remove free lithium hydroxide contained in a positive electrode ink composition before coating and drying by using the specified organic acid compound. SOLUTION: In order to substantially remove free lithium hydroxide contained in a positive electrode ink composition, an organic acid compound of an organic substance selected from the group comprising C1 -C4 carboxylic acid, C2 -C4 fluorcaroboxylic acid, an anhydride of them, and a mixture of them is used. The organic acid compound is C1 -C4 monocarboxylic acid and C2 -C4 polycarboxylic acid, and selected from oxalic acid, formic acid, acetic anhydride, and especially from acetic acid or trifluoroacetic acid. The positive electrode ink composition contains a lithium salt which is produced by the reaction of the organic acid compound with free lithium hydroxide existing in a positive active material so that a base mixture and the ink composition do not substantially contain free lithium hydroxide. The free lithium hydroxide is removed as the lithium salt. |
