Cathode CEI Preformation for Higher First-Cycle Efficiency
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Solution Overview
Problem
Conventional rechargeable batteries face challenges in achieving high first cycle coulombic efficiency due to the formation of cathode electrolyte interphase (CEI) during the initial cycle, which consumes lithium and affects battery performance.
Innovation Solution
A method for pre-forming cathode electrolyte interphase on electroactive materials by ionizing cations at a cation source in an electrochemical reactor, using a cathode active material, electrolyte, and additives, with controlled current or voltage application to form a stable CEI structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rechargeable batteries operate by reversibly passing ions between electrodes, then the battery can supply power to load devices, but the formation of cathode electrolyte interphase during the initial cycle consumes lithium and reduces first cycle coulombic efficiency
Solution Approach 1:
The patent applies preliminary action by pre-forming the cathode electrolyte interphase (CEI) on the cathode active material before assembling the complete battery. This is achieved by contacting the cathode active material with the electrolyte and applying a voltage to form the CEI layer in advance, so that during subsequent battery operation, the CEI is already formed and does not consume additional lithium, thereby improving first cycle coulombic efficiency
2Stability of the object's composition
If a voltage is applied to ionize cations at the cation source in an electrochemical reactor, then a stable CEI structure can be formed on the cathode active material, but the process requires additional equipment and process complexity
Solution Approach 1:
The patent merges the CEI formation process with the battery assembly process by integrating the electrochemical reactor step into the manufacturing workflow. The cathode active material is contacted with electrolyte in a controlled environment, and voltage is applied to form the CEI layer before the cathode is assembled into the final battery, combining two separate operations into a streamlined manufacturing process
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
Enhances the first cycle coulombic efficiency by mitigating CEI formation during the initial cycle, leading to improved battery performance and efficiency.
Implementation Method 1
sourcing a current or voltage to an electrochemical reactor including a cation source, an electrolyte mixture, one or more additives, and a cathode active material in contact with one another, wherein the current or voltage serves to ionize and form cations at the cation source
Implementation Method 2
sourcing a current or voltage to an electrochemical reactor including a cation source, an electrolyte mixture, one or more additives, and a cathode active material in contact with one another, wherein the current or voltage serves to ionize and form cations
Data Source
AI summary
A method for pre-forming cathode electrolyte interphase on electroactive material, the method comprising sourcing a current or voltage to an electrochemical reactor comprising a cation source, an electrolyte mixture, one or more additives, and a cathode active material in contact with one another, wherein the current or voltage serves to ionize and form cations at the cation source that reacts with the cathode active material to pre-form cathode electrolyte interphase on the cathode active material.