Put the fully charged battery on a flat surface, and use a steel needle to pierce the battery radially, which is to test whether the battery catches fire or explodes. In daily use, the battery may be short-circuited due to being penetrated by foreign objects. So the test can well reflect the occurrence of battery short circuits. When the steel needle penetrates, the steel needle provides a short-circuit path inside the battery, and the electric energy of the battery is converted into heat energy and stored inside the battery. The short circuit causes the concentrated explosion and release of energy in a short period, which may cause smoke and leakage. Even catch fire and explode.
the principle of internal short circuits triggered by nail penetration
However, high-energy lithium-ion batteries can pass the acupuncture test through the improvement of battery materials and structural design. So take our high-energy series of solid-state batteries as an experiment for demonstration.
Battery Nail Penetration Test
Ternary High Nickel Liquid Battery VS Solid-State Battery
The battery is charged to 4.2V at 1C constant current,
charged to cut off current of 0.05C at constant voltage.
Use a 5mm steel needle (the conical angle of the needle tip is 45°,
and the surface of the needle is smooth and free of dirt)
to penetrate from the direction perpendicular to the battery
at the speed of 25mm / s. The penetrating position is close
to the center of the battery surface, and the steel needle
stays in the battery for observation for 1h.
Surface Temperature over 450°C
No fire, no fog
Surface Temperature 30°C, Keep Working
There are many safety problems in liquid lithium batteries.
The electrolyte is an organic liquid, and the tendency of side reactions, oxygenolysis, gas generation, and combustion
will aggravate at high temperatures. However, with solid-state battery technology, these problems can be solved perfectly.
Solid-state batteries use non-flammable solid electrolytes to replace the volatile and flammable liquid electrolytes in
traditional lithium-ion batteries, which are generally believed to effectively improve battery safety. In conclusion,
the main reason for the flammability of lithium batteries is that the electrolyte that conducts ions is extremely flammable.
However, solid-state batteries can reduce or even not use electrolytes at all, which not only solves
the flammability problem but also improves battery life.