Battery-Capacitor Parallel Storage for Longer Cycle Life
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Solution Overview
Problem
Existing energy storage systems for handheld devices and electric cars primarily focus on extending battery discharge life without considering the impact of dynamic response on battery cycle life, leading to reduced electricity quality and premature battery degradation.
Innovation Solution
An energy storage system comprising a secondary battery and a capacitor connected in parallel, with a DC/DC converter configuring the equivalent series resistor to be larger than the internal resistor, effectively decoupling transient voltage and smoothing ripple current, thereby enhancing battery cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a capacitor with very low equivalent series resistor is disposed between battery and load, then voltage drop on battery is reduced and discharge-life time is extended, but battery cycle life is not considered and electricity quality is affected by secondary battery's dynamic response
Solution Approach 1:
The patent changes the resistance parameter of the equivalent series resistor to be larger than the internal resistor of the battery, which is opposite to conventional designs. This parameter change resolves the contradiction by preventing harmful transient currents while maintaining voltage stability, thereby extending both discharge-life time and battery cycle life simultaneously.
Solution Approach 2:
The capacitor device acts as an intermediary between the battery and the load, but with a specifically designed equivalent series resistor that mediates the current flow. This intermediary function filters out harmful transient currents while allowing useful current flow, thus protecting the battery and improving electricity quality without sacrificing discharge-life time.
2Loss of energy
If capacitor with low equivalent series resistor is used, then transient current consumption is reduced, but electricity quality deteriorates due to dynamic response effects
Solution Approach 1:
The patent inverts the conventional approach by setting the equivalent series resistor parameter to be larger than the battery's internal resistor. This parameter change reduces transient current consumption while simultaneously improving electricity quality by filtering out high-frequency noise and dynamic response effects that would otherwise degrade power quality.
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 system significantly increases battery cycle life by stabilizing output electricity and reducing dynamic response effects, leading to extended operation time and reduced capacity decline.
Implementation Method 1
a capacitor device, electrically connected to the first terminal and the second terminal in parallel, and the capacitor device has an equivalent series resistor
Implementation Method 2
a DC/DC converter, electrically connected between the first terminal and the capacitor device
Data Source
AI summary
An energy storage system has a battery device, a first terminal, a second terminal, a capacitor device and a DC/DC converter. The first and second terminals are respectively connected two electrodes of the battery device, and the two electrodes have opposite polarities. The capacitor device is electrically connected to the first and second terminals in parallel. The DC/DC converter is electrically connected between the first terminal and the capacitor device. The battery device composed of at least one secondary battery and the capacitor device composed of at least one capacitor are electrically connected to each other in parallel, and by combining with the DC/DC converter, configuring the relation between the equivalent series resistor of the capacitor device and the internal resistor of the battery device, and/or configuring the upper current limit of the rated current of range the DC/DC converter, the battery cycle life is increased.