1. Low battery capacity
Reason for occurrence:
a. The amount of auxiliary materials is too small;
b. The amount of material adhering to both sides of the electrode differs significantly;
c. Electrode breakage;
d. Low electrolyte content;
e. Low electrolyte conductivity;
f. The positive and negative electrode plates are not properly matched;
g. The membrane has low porosity;
h. Adhesive aging → Material detachment;
i. The core is too thick (not dried or the electrolyte has not penetrated).
j. Not fully charged during capacity testing;
k. The specific capacity of the positive and negative electrode materials is small.
2. High internal resistance of the battery
Reason for occurrence:
a. Poor soldering between the negative electrode and the electrode tab;
b. Poor soldering between the positive electrode plate and the electrode tab;
c. Poor soldering between the positive electrode tab and the cap;
d. The negative electrode lug is poorly soldered to the casing;
e. The contact resistance between the rivet and the pressure plate is high;
f. No conductive agent was added to the positive electrode;
g. The electrolyte contains no lithium salts;
h. The battery has experienced a short circuit;
i. The diaphragm paper has low porosity.
3. Low battery voltage
Reason for occurrence:
a. Side reactions (electrolyte decomposition; impurities at the positive electrode; presence of water);
b. Not yet fully formed (SEI film not yet safely formed);
c. Leakage in the customer's circuit board (referring to the battery cells returned by the customer after processing);
d. The customer did not spot weld the battery cells as required (after customer processing);
e. Burrs;
f. Micro-short circuit;
g. Dendrites appear at the negative electrode.
4. The reasons for the occurrence of excessive thickness are as follows:
a. Air leakage at the weld;
b. Electrolyte decomposition;
c. Undried moisture;
d. Poor sealing performance of the cap;
e. The shell wall is too thick;
f. The shell is too thick;
g. The core is too thick (too much material; the electrode sheet is not compacted; the diaphragm is too thick).
5. Abnormal battery formation
a. Incomplete or incomplete SEI film;
b. Baking temperature too high → adhesive aging → material release;
c. Low specific capacity of the negative electrode;
d. There is more attached material at the positive electrode and less attached material at the negative electrode;
e. The cap is leaking air, and the weld is leaking air;
f. Electrolyte decomposition leads to a decrease in conductivity.
6. Battery explosion
a. The capacity divider is faulty (causing overcharging);
b. Poor diaphragm closure effect;
c. Internal short circuit.
