Nail Penetration Test Confirms Safety of Jiuwu's Semi-Solid Battery

How to strike the perfect balance between high energy density and ultimate safety is a core challenge that battery material suppliers, cell manufacturers, and automotive OEMs worldwide are collectively striving to solve. Recently, Jiuwu Hi-Tech conducted a comparative nail penetration test between semi-solid-state batteries and conventional liquid batteries, based on the national standard GB 31485-2015. Using the most intuitive and rigorous experimental data, the test revealed the real-world safety performance of semi-solid-state batteries under extreme conditions. The results demonstrated that semi-solid-state batteries using Jiuwu's self-developed LATP material showed no combustion or explosion, marking a substantial improvement in safety.

In actual use, batteries may be subjected to various extreme abuse scenarios, including squeezing, collision, overcharging, heating, and puncture by sharp objects. Among all safety tests, the nail penetration test is the most stringent and the one that most closely simulates real-world hazardous conditions.

Its core principle is as follows: a rigid steel needle rapidly pierces through the battery cell, forcibly creating direct contact between the positive and negative electrodes and causing an internal short circuit. This instantly releases a large amount of heat, thereby testing whether the battery will experience fatal hazards such as fire, explosion, or thermal runaway under unavoidable physical damage. Compared to other tests, the nail penetration test is more unpredictable and triggers short circuits more directly, making it the "gold standard" for verifying battery safety limits.

This test strictly followed the GB 31485-2015 "Safety Requirements for Traction Batteries of Electric Vehicles" and was conducted entirely in a standardized laboratory environment. All parameters, procedures, and results are authentic and traceable, with the sole purpose of revealing the true safety performance of batteries under extreme mechanical damage.

To ensure the fairness and comparability of the experimental results, variables were strictly controlled in this comparative test. The only difference between the two battery groups was their separator and electrolyte systems. All other core materials, specifications, and test conditions were kept completely identical, eliminating external factors to the greatest extent possible, so that any safety differences stemmed entirely from the technology systems themselves.

Semi-Solid Battery: No Fire, No Explosion, No Smoke — Casing Intact

Visual Recording Throughout the Test: When a 3mm steel needle penetrated the semi-solid battery at a constant speed of 8mm/s, the battery remained stable throughout the entire process — no fire, no explosion, no smoke emission, and no casing rupture or deformation.

According to professional temperature monitoring equipment, the maximum surface temperature rise of the battery at the moment of nail penetration was less than 40°C. Only slight local heating occurred at the penetration point, and the heat dissipated rapidly, completely failing to trigger a chain thermal runaway reaction. After the test, with the steel needle removed, the battery structure remained intact with no electrolyte leakage. Its safety performance significantly exceeded national standard requirements.

Liquid Battery: Thermal Runaway Spread — Full Safety Hazard

Under identical test conditions, the moment the steel needle made contact and pierced the liquid battery, the battery immediately reacted violently. Flames quickly ignited, accompanied by a violent explosion, and large amounts of thick black smoke erupted. The battery casing rapidly deformed and was burned away.

Temperature data shows that the maximum surface temperature rise of the battery at the moment of nail penetration exceeded 400°C. Within a short period, full-scale thermal runaway was triggered, and the heat rapidly spread throughout the entire cell, ultimately burning it completely. The safety hazards of liquid battery are alarming.