Redox Flow Battery Pump Controller for Overcharge Prevention
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Solution Overview
Problem
Redox flow batteries face inefficiencies due to overcharge and overdischarge, leading to decreased battery capacity and efficiency, as well as increased pumping losses, which can result in gas generation and adherence of metal ions to electrodes, causing operational instability.
Innovation Solution
A redox flow battery system with a pump controller that measures inlet and outlet state of charge and charge/discharge current to calculate and adjust pump flow rates, preventing overcharge and overdischarge by optimizing flow rates based on charge/discharge efficiency, thereby maintaining stable operation and reducing pumping losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If pump flow rates are constantly set to fixed values, then the redox flow battery can operate continuously, but large pumping losses are caused and battery efficiency decreases
Solution Approach 1:
The pump flow rates are made dynamically adjustable rather than fixed. The control unit varies the flow rates of the first and second pumps based on the state of charge (SOC) of the electrolyte, allowing the system to adapt to different operating conditions and minimize pumping losses while maintaining continuous operation.
Solution Approach 2:
The system changes the operational parameters (flow rates) of the pumps based on the SOC of the electrolyte. By adjusting the flow rates according to charge state, the system optimizes energy efficiency across different operating phases while ensuring continuous battery operation.
2Loss of energy
If pump flow rates are adjusted corresponding to states of charge, then pumping losses are decreased, but overcharge and overdischarge of electrolytes occur
Solution Approach 1:
The system implements feedback control by continuously monitoring the state of charge (SOC) of the electrolyte and using this information to adjust pump flow rates. The control unit receives SOC signals and dynamically adjusts the pump operations to prevent overcharge and overdischarge while maintaining energy efficiency.
Solution Approach 2:
The system replaces simple mechanical flow rate adjustment with an intelligent control system that uses electrical signals and computational logic. The control unit processes SOC information and automatically adjusts pump flow rates, substituting manual or fixed mechanical control with an automated electronic control system that prevents charge instability.
3Quantity of substance
If electrolytes are overcharged, then battery capacity increases, but gas is generated and metal ions precipitate in the battery cell
Solution Approach 1:
The system takes preliminary action to prevent overcharge by monitoring the state of charge (SOC) and adjusting pump flow rates before overcharge conditions develop. The control unit proactively reduces or stops electrolyte circulation when approaching maximum charge levels, preventing gas generation and metal ion precipitation that would occur with overcharging.
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 effectively suppresses overcharge and overdischarge, enhancing battery efficiency and capacity by dynamically adjusting pump flow rates, ensuring continuous and stable charge/discharge operations while minimizing pumping losses.
Implementation Method 1
The electrolytes are aqueous solutions containing metal ions (active materials) that undergo changes in valence by oxidation-reduction
Implementation Method 2
a pump that causes the electrolyte to circulate through the circulation piping
Data Source
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AI summary
Provided are a redox flow battery system and a method for operating a redox flow battery that suppress overcharge and overdischarge of an electrolyte. A redox flow battery system includes a pump that supplies an electrolyte to a battery cell by circulation, a pump controller that controls a flow rate of the pump, and a measurement unit that measures at least two parameters selected from among an inlet-side state of charge of the electrolyte supplied to the battery cell, an outlet-side state of charge of the electrolyte drained from the battery cell, and a charge/discharge current input to/output from the battery cell. The pump controller includes a pump flow-rate computation unit that calculates a charge/discharge efficiency of the battery cell from the parameters measured by the measurement unit and, based on the charge/discharge efficiency, determines the flow rate of the pump so that the electrolyte drained from the battery cell is neither overcharged nor overdischarged. The pump controller also includes a pump flow-rate instruction unit that sets in the pump the flow rate determined by the pump flow-rate computation unit.