This quick-sampling test can easily detect an internal lithium-ion battery short circuit prior to operation, reducing the chance of damage to electronic devices. Lithium-ion batteries are high-energy, rechargeable batteries usable in several products, including electric vehicles, smartphones and laptops. However, these batteries occasionally suffer from internal short circuits (ISC), resulting in fires and presenting a critical safety issue. Additionally, current methods for detecting short circuits rely entirely on sensors which can report inaccurate readings if they are left operational for a long period of time.
Researchers at the University of Florida have developed a quick-sampling test which can quickly and accurately estimate the short-circuit resistance of lithium-ion batteries. Combining a resistor and inductor-based technique improves internal short-circuit detection, preventing complete battery failure.
Combined resistor and inductor-based detection circuits for internal short-circuit identification
Two detection circuits work to identify internal short circuits. In the resistor-based circuit, a test resistor and a switch connect in parallel with a battery load. A transient current travels through the first and second external battery terminals when the switch is turned on. This technique measures internal resistance and identifies short circuits. In the inductor-based circuit, a measurement resistor and an H-bridge comprised of an inductor and four switches lie adjacent to a battery. The top ends of the H-bridge connect to the battery's first terminal and the bottom ends connect to its second terminal. Once the two switches turn on, the measurement resistor records the transient current passing through and detects internal short circuits. The use of these two techniques can detect the internal short circuit in real-time operation of a battery.