Heating Element Circuit Managing ESR in Energy Storage Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Energy storage cells face inefficiencies due to equivalent series resistance (ESR), which increases with age and is inversely proportional to temperature, affecting charging and discharging capabilities and lifespan.
Innovation Solution
A system comprising a heating element thermally coupled with an energy storage cell, a thermistor, and a processing circuit that converts temperature data into a pulse-width-modulated signal to control the ESR by maintaining the cell at or above a target temperature, using firmware to adjust the heating element's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the energy storage cell operates at low temperature, then the ESR increases, but the charging and discharging efficiency decreases
Solution Approach 1:
The patent changes the temperature parameter of the energy storage cell by applying controlled heating. The system monitors cell temperature and applies heat when the temperature falls below a threshold, thereby changing the thermal state of the cell to maintain optimal ESR characteristics and charging/discharging efficiency.
Solution Approach 2:
The patent implements a feedback control system that continuously monitors the temperature of the energy storage cell and adjusts the heating element accordingly. When the temperature drops below a set point, the heating element is activated; when the temperature reaches the set point, heating is reduced or stopped, creating a closed-loop control system.
2Temperature
If the heating element is continuously activated, then the temperature is maintained, but the energy consumption increases
Solution Approach 1:
The patent employs periodic or intermittent heating rather than continuous heating. The heating element is activated only when the temperature sensor detects that the cell temperature has dropped below a predetermined threshold, and deactivated when the threshold is reached, creating a periodic on-off heating pattern that reduces overall energy consumption.
Solution Approach 2:
The energy storage cell itself provides the basis for controlling the heating process through its own temperature characteristics. The system uses the cell's temperature feedback to automatically regulate heating, allowing the cell to essentially control its own thermal management without external intervention.
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
This approach dynamically manages ESR, enhancing charging efficiency, reducing the need for over-provisioning, and extending the lifespan of energy storage cells by maintaining optimal temperature, thus improving their availability and usage over time.
Implementation Method 1
a heating element in thermal communication with the energy storage cell
Implementation Method 2
a thermistor coupled to the energy storage cell
Data Source
AI summary
An apparatus and method of keeping an energy storage cell at or above a target temperature, includes receiving at a processing circuit, an analog voltage that is proportional to a temperature of the energy storage cell, converting, at the processing circuit, the analog voltage to a pulse-width-modulated signal having a duty cycle that is proportional to the analog voltage, and driving a switch, with the pulse-width-modulated signal, between conductive and non-conductive states to modulate a voltage passing across (or a current flowing through) a heating element in series with the switch, the heating element being in thermal communication with the energy storage cell, wherein the duty cycle of the pulse-width-modulated signal is adjusted to maintain the temperature of the energy storage cell at or above the target temperature.