Oxygen-Consuming Battery Sacrificial Drain High Rate Capability
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Solution Overview
Problem
Oxygen-consuming electrochemical batteries, such as metal/air cells, face challenges in maintaining high rate and high power discharge capability due to limitations in oxygen diffusion rates, which can lead to cell deterioration from impurities like carbon dioxide, and existing solutions like fans and valves add complexity and cost.
Innovation Solution
Incorporating a sacrificial drain mechanism that puts the battery on a light discharge when not in use, using a high resistance load between the terminals, to reduce the impact of impurities and maintain discharge capacity and rate capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If oxygen diffusion rate is increased to improve high rate discharge capability, then power delivery is improved, but entry of impurities like carbon dioxide increases causing cell deterioration
Solution Approach 1:
The patent applies a dynamic approach by using a valve that can open and close based on operating conditions. During high rate discharge, the valve opens to allow high oxygen diffusion rates for maximum power delivery. During low rate discharge or storage, the valve closes to prevent impurity entry and cell deterioration. This dynamic control resolves the contradiction by adapting the oxygen diffusion rate to the actual power demand.
Solution Approach 2:
The patent changes the parameter of oxygen diffusion rate dynamically through valve control. By adjusting the valve position, the system can switch between high diffusion rates (for power delivery) and low diffusion rates (for preserving cell integrity), thereby resolving the contradiction between power capability and reliability.
2Power
If valve or fan mechanisms are added to control air flow, then oxygen entry rate is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent employs a self-service mechanism where the valve is automatically actuated by pressure differential caused by oxygen consumption during discharge. The system uses its own operating conditions (pressure changes from oxygen depletion) to control the valve, eliminating the need for external fans, pumps, or electronic controls. This self-regulating approach improves oxygen entry rate while avoiding added complexity.
Solution Approach 2:
The patent uses pneumatic principles by leveraging pressure differential (a gas pressure phenomenon) to actuate the valve. The pressure changes resulting from oxygen consumption during discharge automatically open or close the valve, providing a simple, passive control mechanism that avoids complex electronic or mechanical systems.
3Power
If valve mechanisms are added to control air flow, then oxygen entry rate is improved, but cell volume available for active material decreases
Solution Approach 1:
The patent uses a thin membrane or flexible diaphragm as the valve structure. This thin-film approach provides effective flow control with minimal volume occupation, preserving maximum cell volume for active materials while still achieving the desired oxygen entry rate control.
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 minimizes cell deterioration and maintains high rate capability by reducing the entry of impurities during non-use periods, thereby extending the battery's useful life and performance.
Implementation Method 1
Oxygen enters the cell, where it can be used as an active material in the oxygen consuming (e.g., positive) electrode, where the oxygen consuming electrode promotes the reaction of the oxygen with the cell electrolyte and, ultimately, oxidation of the counter (e.g., negative) electrode active material.
Implementation Method 2
The maximum discharge rate can limited by the rate at which oxygen can enter the oxygen consuming electrode.
Data Source
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AI summary
An oxygen-consuming battery, such as a metal-air cell or fuel cell battery using oxygen from outside the battery as an active material, and having an improved high rate capability is disclosed. After the battery has been put into use, a light sacrificial drain is placed on the battery during periods when the battery is not being used to provide power in order to reduce degradation in rate capability that can occur over time, particularly when the battery is being used intermittently. Also disclosed is a combination of the oxygen-consuming battery and an electronic device that can be powered by the battery.