Ultrasound-equipped battery prevents potential fires with sound waves
A new type of lithium-ion battery that uses ultrasound to detect and prevent internal short circuits could make battery fires a thing of the past.
Lithium-ion batteries are widely used in portable devices, electric vehicles and renewable energy systems, but they can pose a fire hazard if they overheat or are damaged. This can happen when a metal filament called a dendrite grows inside the battery and pierces the separator between the positive and negative electrodes, causing a short circuit.
Researchers from Stanford University and the Samsung Advanced Institute of Technology have developed a battery that can prevent this scenario by using ultrasound waves to monitor the growth of dendrites. The battery has a thin layer of piezoelectric material that converts electrical energy into mechanical vibrations and vice versa. The piezoelectric layer acts as both a sensor and an actuator, sending and receiving ultrasound signals that reflect the state of the battery.
When the battery is charging, the piezoelectric layer emits ultrasound waves that bounce off the electrodes and return to the sensor. If a dendrite starts to form, it will change the acoustic impedance of the battery and alter the ultrasound signal. The sensor can detect this change and trigger an alarm or stop the charging process. Alternatively, the piezoelectric layer can also generate high-intensity ultrasound waves that can break up the dendrite and restore the normal function of the battery.
The researchers tested their ultrasound-equipped battery in various conditions and found that it could reliably detect and prevent short circuits without affecting the performance or capacity of the battery. They also showed that the ultrasound technique could work with different types of electrodes and electrolytes, making it compatible with existing and future battery technologies.
The researchers hope that their invention could lead to safer and more reliable batteries for various applications, especially those that require high energy density and long cycle life. They also plan to further optimize the design and integration of the piezoelectric layer and explore other ways to use ultrasound for battery diagnostics and management.
The ultrasound-equipped battery is not the only solution to the dendrite problem. Other researchers have tried to use different materials, coatings, additives or separators to inhibit or dissolve the growth of dendrites. However, these methods may have drawbacks such as increasing the cost, complexity or weight of the battery, or reducing its performance or lifespan.
The advantage of the ultrasound technique is that it does not require any modification of the battery components or chemistry, and it can be easily integrated into existing battery systems. It also offers a real-time and non-invasive way to monitor and control the battery state, which could improve the safety and efficiency of battery operation and management.
The researchers estimate that the cost of adding the piezoelectric layer to a battery would be negligible compared to the benefits of preventing potential fires and extending battery life. They also believe that their ultrasound technique could be applied to other types of batteries, such as solid-state or metal-air batteries, that may also suffer from internal short circuits. aa16f39245