Negative pressure formation method for lithium iron manganese phosphate batteries and batteries applying the same

A lithium iron manganese phosphate battery, wherein a cathode active coating layer of the lithium iron manganese phosphate battery comprises lithium iron manganese phosphate material, and the lithium iron manganese phosphate battery is subjected to a negative pressure formation method, the method comprising following steps:

• performing a vacuumizing process, a resting process and a charging process for a semi-finished battery cell to obtain a post-formation battery cell;
• the charging process is a three-stage constant-current charging process, wherein in the three-stage constant-current charging process, a charging current I, and a state of charge S are required to satisfy following relations:
• in a first stage constant-current charging process, I1≤0.1 C, state of charge:
• 5%≤S1≤15%;
• in a second stage constant-current charging process, 0.05 C≤I2≤0.15 C, state of charge:
• 15%≤S2≤25%;
• and
• in a third stage constant-current charging process, 0.15 C≤I3≤0.25 C, state of charge:
• 35%≤S3≤45%.