Patent ID: 11967687
Assignee: SHENZHEN JIECHENG NICKEL COBALT NEW ENERGY TECHNOLOGY CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  B  Y | IPC B  H

Claim 0:
1. A safe discharge method for waste lithium ion batteries, comprising following steps:
S1: uniformly mixing the waste lithium ion batteries and conductive particles in a discharge chamber according to a weight ratio of 1:5-2:1; wherein a resistance of the conductive particles ranges from 0.1-20Ω; a particle size of the conductive particles ranges from 1-10 mm;
S2: compacting the waste lithium ion batteries and the conductive particles at a pressurization pressure of 1000-100000 Pa, so that the waste lithium ion batteries discharge; calculating an internal resistance of the discharge chamber in real time according to the pressurization pressure; calculating a discharge rate of the waste lithium ion batteries in combination with a battery voltage and a rated capacity of the waste lithium ion batteries; dynamically adjusting the pressurization pressure to keep the discharge rate of the waste lithium ion batteries to be 0.1-3 C; monitoring an internal temperature of the discharge chamber in real time; when the internal temperature of the discharge chamber is greater than an early warning temperature, reducing the pressurization pressure by 20%-60%; when the internal temperature of the discharge chamber is greater than a warning temperature, relieving the pressurization pressure to 0 Pa, reducing the pressurization pressure by 60%-90% after the internal temperature of the discharge chamber drops below the early warning temperature; and re-compacting the waste lithium ion batteries and the conductive particles to discharge the waste lithium ion batteries; and
S3: completing discharge of the waste lithium ion batteries, when the battery voltage of the waste lithium ion batteries is reduced to 0.5-1.5 V, or when the waste lithium ion batteries are discharged for 1-4 h after the internal temperature of discharge chamber is reduced to room temperature;
wherein in the step S2, a process of dynamically adjusting the pressurization pressure is represented by:

C=U/(R*Ca);

R=R0+Rj;

Rj=K/Fm;

wherein C is the discharge rate of the waste lithium ion batteries; U is the battery voltage of the waste lithium ion batteries; Ca is the rated capacity of the waste lithium ion batteries; R is the internal resistance of the discharge chamber; R0 is the resistance of the conductive particles; Rj is a contact resistance between the conductive particles; F is the pressurization pressure, K is a constant related to a contact material, a contact surface processing method, and a contact surface condition; m is a constant related to a contact form, and m is 0.5-0.7.