Metal Conversion Battery First-Charge Activation for Stable Capacity
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Solution Overview
Problem
Existing metal conversion batteries face challenges in accessing full theoretical capacity, experiencing undesirable phase formation at higher temperatures, and suffer from unstable capacity and resistance during early cycles, limiting their performance and cycle life.
Innovation Solution
A method involving an excess overpotential during the first charging cycle and maintaining the battery at a higher temperature throughout the entire charge process, while using earth-abundant materials like iron and sodium, to form batteries with improved capacity and stability, avoiding the use of additives that react with the cathode metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the battery is charged at higher temperature throughout the entire first charge, then the battery can access greater proportions of theoretical capacity, but this may result in undesirable phase formation and hinder battery performance
Solution Approach 1:
The patent applies preliminary action by performing a specific first charge cycle at elevated temperature (325°C) before normal operation. This preliminary high-temperature charge activates the cathode material and enables subsequent cycles to access greater capacity without the harmful phase formation that would occur during normal operation, effectively preparing the battery in advance for optimal performance.
Solution Approach 2:
The patent applies partial or excessive action by using an excess overpotential (at least 150 mV above open circuit voltage) during the first charge cycle. This excessive electrical potential, combined with elevated temperature, forces complete conversion of the cathode material and activates trapped surface area on iron particles, achieving 90% or more of theoretical capacity that would not be accessible under normal charging conditions.
2Reliability
If conventional charging methods are used, then the battery operates safely, but only about 10% of theoretical battery capacity is accessed after the first cycle
Solution Approach 1:
The patent applies preliminary action by performing a specific first charge cycle at elevated temperature (325°C) before normal operation. This preliminary high-temperature charge activates the cathode material and enables subsequent cycles to access greater capacity without the harmful phase formation that would occur during normal operation, effectively preparing the battery in advance for optimal performance.
Solution Approach 2:
The patent applies parameter changes by temporarily modifying charging parameters (temperature to 325°C and overpotential to exceed open circuit voltage by at least 150 mV) during the first charge cycle only. These parameter changes enable access to trapped surface area and improve capacity without affecting the safety and stability of subsequent normal operation cycles.
3Productivity
If additives are used to improve battery performance, then capacity may be enhanced, but the additives react with the cathode metal and reduce cycle life
Solution Approach 1:
The patent applies self-service by using the battery's own operational parameters (elevated temperature and excess overpotential during first charge) to activate the cathode material and access trapped surface area, eliminating the need for external additives. The battery system uses its inherent capabilities to achieve improved capacity without introducing substances that would react with and degrade the cathode metal over time.
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 method enables batteries to access up to 90% of theoretical capacity after the first cycle, with stable performance and long cycle life, suitable for grid energy storage, and reduces the need for costly additives, achieving high energy density and low resistance.
Implementation Method 1
applying a first charge to the battery, applying a first discharge to the battery, cycling the battery (e.g., through charge and discharge cycles)
Implementation Method 2
maintaining the battery at an elevated temperature throughout an entire first charge
Data Source
AI summary
A method can include loading a battery with battery materials (e.g., electrolyte, cathode materials, anode materials), applying a first charge to the battery, applying a first discharge to the battery, cycling the battery (e.g., through subsequent charge and discharge cycles) where operating conditions in the subsequent charge and/or discharge cycles can be different from operating conditions in the first charge and/or first discharge.