CDOT Device Interdigitated Electrodes Wireless Charging Thermal Runaway
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Solution Overview
Problem
Wireless charging can cause thermal runaway in lithium-ion batteries due to excess heat generated by the magnetic field from induction coils, leading to potential damage and reduced battery life.
Innovation Solution
A Charge/Discharge Over Temperature (CDOT) device with interdigitated electrodes and a variable resistance material is connected in series with the wireless charging coil, providing temperature detection and overcurrent protection to mitigate thermal runaway by adjusting resistance in response to temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless charging is used to charge the battery, then charging convenience is improved, but excess heat is generated causing thermal runaway risk
Solution Approach 1:
The patent introduces a magnetic field shielding layer as an intermediary component between the wireless charging coil and the battery. This shielding layer selectively blocks excessive magnetic field energy from reaching the battery, thereby reducing heat generation during wireless charging while maintaining charging functionality. The shielding material acts as a mediator that filters harmful thermal energy while allowing necessary charging operations to proceed.
Solution Approach 2:
The patent converts the harmful thermal runaway risk into a beneficial safety mechanism by implementing temperature monitoring and controlled discharge systems. When excessive heat is detected, the system automatically reduces charging power or terminates charging, transforming the potential hazard into a protective feature that prevents battery damage while maintaining safe charging operations.
2Productivity
If rapid charging is performed to reduce charging time, then charging speed is improved, but thermal runaway risk increases due to excess heat
Solution Approach 1:
The patent implements dynamic charging control that adjusts charging parameters in real-time based on battery temperature and charge state. The system transitions between different charging modes (rapid charging, standard charging, or termination) depending on thermal conditions, allowing maximum charging speed when safe and automatically reducing speed when temperature thresholds are approached, thus resolving the contradiction between speed and safety.
Solution Approach 2:
The patent incorporates temperature sensing and feedback control mechanisms that continuously monitor battery thermal state during charging. When temperature exceeds safe thresholds, the system provides feedback to reduce or terminate charging current, creating a closed-loop control system that maintains rapid charging within safe thermal boundaries by dynamically adjusting power delivery based on real-time thermal feedback.
3Quantity of substance
If overcharging is performed to maximize battery capacity utilization, then energy storage is improved, but battery damage occurs reducing battery life
Solution Approach 1:
The patent implements preliminary protective measures including voltage and charge-state monitoring systems that detect approaching overcharge conditions before they cause damage. The system proactively reduces or terminates charging current when safe thresholds are approached, preventing battery stress and extending battery life while maximizing safe energy storage utilization through predictive charge management.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The CDOT device effectively prevents thermal runaway by limiting current and voltage during charging, ensuring safe operation and extending battery life without affecting the magnetic field or charging efficiency.
Implementation Method 1
The variable resistance material changes its resistance in response to a change in temperature
Implementation Method 2
a type of induction charging known as the Qi wireless standard allows the battery to be charged in the presence of a magnetic field. The charging device includes an induction coil and the mobile device include a second induction coil. Together, the coils create a magnetic field that sends electric current to charge the battery
Implementation Method 3
The first fingers and the second fingers are disposed in an interdigitated, spaced-apart relationship with one another, resulting in a gap between them that is serpentine and tortuous
Data Source
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AI summary
A battery protection device includes a Charge/Discharge Over Temperature (CDOT) device and a wireless charging coil. The CDOT device consists of a first electrode, a second electrode, and a variable resistance material. The first electrode is located on a substrate and has a first collection of fingers. The second electrode is located on the substrate and has a second collection of fingers. The first fingers and the second fingers are disposed in an interdigitated, spaced-apart relationship with one another, resulting in a gap between them that is serpentine and tortuous. The variable resistance material changes its resistance in response to a change in temperature.