1. Low battery voltage
Side reactions (electrolyte decomposition; impurities in the positive electrode; presence of water); leakage current in the customer's circuit board (referring to the battery cells returned after processing by the customer); spot welding not performed by the customer as required (for the battery cells after processing by the customer); burrs; micro-short circuits; dendrites appearing on the negative electrode.
2. The reasons for the malfunction due to excessive thickness are as follows:
Air leakage at the weld; electrolyte decomposition; insufficient drying of moisture; poor sealing of the cap; shell wall too thick; shell too thick; core too thick (too much material attached; electrode not compacted; diaphragm too thick).
3. Abnormal battery formation
Incomplete or incomplete SEI film formation; excessively high baking temperature → adhesive aging → material detachment; low specific capacity of negative electrode; excessive positive electrode material while insufficient negative electrode material material; air leakage in cap and weld; electrolyte decomposition and reduced conductivity.
4. Low battery capacity
Causes: Insufficient material content; significant difference in material content on both sides of the electrode; insufficient electrolyte; low electrolyte conductivity; low diaphragm porosity; excessively thick core (not dried or not fully permeated by electrolyte), resulting in insufficient charging during capacity testing; low specific capacity of positive and negative electrode materials.
5. Battery short circuit
Dust; damage during packaging; scraping (divider paper too small or not properly padded); uneven winding; not properly packaged; holes in the divider;
6. High internal resistance of the battery
Causes: Poor soldering between negative electrode and tab; poor soldering between positive electrode and tab; poor soldering between positive tab and cap; poor soldering between negative tab and shell; high internal resistance between rivet and pressure plate; no conductive agent added to positive electrode; no lithium salt in electrolyte; battery has been short-circuited before; low porosity of separator paper.
7. Battery open circuit.
The electrode tab and rivet are not properly welded, or the effective weld area is too small;
The connecting piece is broken (the connecting piece is too short or it is welded too low when spot-welded to the electrode).
8. Battery explosion
The capacity divider is faulty (causing overcharging); the diaphragm has poor closure; there is an internal short circuit.
