reaction temperature sensing (rts)-based control for li-ion battery safety
Fundamentally strengthen basic control
Ion battery safety
RTS placed in Li-
The ion battery display detects temperature rise faster and more accurately than the external measurement battery surface temperature.
We proved RTS for the first time-
Close a dangerous short based on control
Circuit events 3 times earlier than surface temperature-
Based on the control, prevent the battery from overheating at 50 °c, resulting in damage to the battery.
As shown in the figure, cylindrical Li-
Ion battery (
Format 18650, diameter 18mm, height 65mm)
Embedded micro-reaction temperature sensor (RTS)
For internal reaction temperature diagnosis.
The micro temperature sensor is located at the front end of the reaction area of the cylindrical Li-
Ion batteries with the highest temperature along the radial direction.
With the traditional cylindrical Li-
Ion batteries, there are four additional steps to make batteries with RTS :(1)
Micro temperature sensor coated with P-px
Corrosion in operation
Conditions of ion pool; (2)
During the winding process, the sensor is embedded in the reaction interface between the negative electrode and the separator near the innermost side of the jelly coil; (3)
Insert the jelly roller with embedded sensor with pre-
A small hole was drilled on the wall for sticking the sensor out of the tank; (4)
Before filling the electrolyte and battery curl, seal the small holes in the wall of the jar with epoxy resin.
The micro-temperature sensor used in this study is the T-type micro-thermocouple (
RTD 600 T)
The wire is 80 um in diameter and 10 um in insulation.
The micro-thermocouple received on the measuring tip is not insulated.
In the nano-processing laboratory of Penn State Institute of Materials, a special parylene evaporator is used to coat a parylene layer of 10 μm at the measuring tip.
Using insulation, the sensor measures the thickness of the tip at 100 Ethereum, the same thickness as the wire.
Place another micro-temperature sensor on the outer surface of the battery to monitor the surface temperature (T)
And compare with RTS.
The experimental battery is used in the battery manufacturing laboratory of Penn State University (NCM)
Graphite is used as positive and negative electrode materials respectively.
The thickness of the positive and negative electrodes is mm and mm, respectively, including the collection of the current collector and the coating on both sides.
The positive collector is aluminum foil with 15 Ethereum and the negative collector is copper foil with 10um um.
The separator Celgard®2320pp PP/PE/PP three-layer film with a thickness of 20 um.
Electrolyte is 1.
EC: EMC: DMC (20:20:60u2009v%).
To verify the effectiveness of RTS, we have developed an experimental system that can trigger and terminate short circuit of experimental Li-ion cell.
The experimental system is illustrated.
Shunt resistance (0. 15u2009mΩ, ±0. 5%, OHMITE, USA)
Used to measure the short circuit current of the battery.
The total external short circuit resistance is 10mm Ω, including all resistors on the outside of the battery, measured by a low resistance meter (
3560 Aoki, Japan).
Temperature Controller (
CN8201, Omega Engineering Company, USA)
And contactor (
LEV200, Tyco Electronics, USA)
Used to start and terminate short circuits. A multi-
Channel data acquisition unit (
34 70A, Agilent Technology Company, USA)
Used to record the internal reaction temperature, surface temperature, current and voltage of the battery during each 0 tests. 5u2009s.
Battery tester (
BT2000, American Arbin Instrument Company)
Used to fully charge the battery before the short circuit test and characterize the battery performance after the short circuit test.
The short circuit test is carried out in a safe chamber providing natural convection cooling conditions.
With constant current, the battery is fully charged-
Constant Voltage (CC-CV)protocol (0. 8u2009A, 4. 2u2009V max, 0. 032u2009A cut-off)
At room temperature (25u2009±u20091u2009°C).
The battery then rests for at least an hour to allow open voltage (OCV)
Before the performance representation after the short circuit test or short circuit test, the battery temperature is balanced.