Negative Electrode Surface Reforming for Lithium Dendrite Removal
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Solution Overview
Problem
Secondary lithium batteries develop undesirable lithium dendrites and surface irregularities on the negative electrode after repeated charging cycles, which affect the battery's performance and require a method to restore the electrode to its original condition.
Innovation Solution
A method and system that utilize a porous sensory layer between the negative and positive electrodes to measure electrical parameters, determining the presence of lithium dendrites and executing a reforming cycle by applying pulsed electric current or voltage to eliminate them, thereby restoring the surface uniformity of the negative electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If repeated charging cycles are performed in secondary lithium batteries, then the battery can be recharged and reused, but lithium dendrites and surface irregularities form on the negative electrode
Solution Approach 1:
The patent applies preliminary action by executing a reforming cycle before lithium dendrites completely bridge the gap between electrodes. The system monitors electrical parameters and triggers reforming when dendrites reach a certain growth stage, preventing them from becoming continuous conductive paths while eliminating surface irregularities. This proactive approach extends cycle life by addressing dendrite formation early in the charging process.
Solution Approach 2:
The patent converts the harmful effect of lithium dendrite formation into a beneficial monitoring signal. The electrical conductivity changes caused by dendrite growth are detected and used to trigger the reforming cycle. By transforming the harmful dendrite formation process into a detectable signal, the system can initiate corrective action that eliminates dendrites and restores electrode surface uniformity, thereby extending battery cycle life.
2Measurement precision
If a porous sensory layer is added to detect lithium dendrites, then detection capability is improved, but device complexity increases
Solution Approach 1:
The porous sensory layer is integrated into the existing battery structure, serving multiple functions simultaneously. It acts as both a separator component and a sensing element that detects lithium dendrite formation through electrical parameter changes. This multi-functional design allows the same structural element to perform both mechanical separation and electrochemical sensing, avoiding the need for separate detection systems and minimizing added complexity.
Solution Approach 2:
The porous sensory layer serves as an intermediary between the negative electrode and the monitoring system. It provides a medium through which electrical parameters can be measured to detect lithium dendrite formation without requiring direct contact with the electrode surface or complex imaging systems. The sensory layer translates physical dendrite growth into measurable electrical signals, simplifying the overall detection architecture.
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 effectively eliminates lithium dendrites and surface irregularities, improving the battery's performance by maintaining the electrode's smooth contour and extending its cycle life.
Implementation Method 1
an electrical parameter is measured. The electrical parameter is associated with a porous sensory layer disposed between a major facing surface of the negative electrode layer and an opposing surface of a positive electrode layer
Implementation Method 2
a reforming cycle is executed. The reforming cycle reforms the major facing surface of the negative electrode layer and eliminates at least a portion of the lithium dendrite
Implementation Method 3
In secondary lithium metal batteries, the released lithium ions are reduced to lithium metal and plated on a surface of the negative electrode current collector in the form of a substantially uniform lithium metal layer
Data Source
AI summary
A method of reforming a negative electrode layer of a secondary lithium battery may include execution of a reforming cycle that reforms a major facing surface of the negative electrode layer by eliminating at least a portion of a lithium dendrite or other lithium-containing surface irregularity that has formed on the major facing surface of the negative electrode layer.