Negative Electrode Profiling for Battery Degradation Diagnosis
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Solution Overview
Problem
Existing battery diagnosis technologies fail to accurately diagnose the state of the negative electrode separately from the positive electrode, especially when an active material like pure silicon undergoes phase transformation, leading to inaccurate capacity assessment and degradation prediction.
Innovation Solution
A method and apparatus that generate a battery profile, obtain a negative electrode profile, and calculate diagnostic factor values to assess the negative electrode's state, allowing separate diagnosis from the positive electrode, even with phase-transforming materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing battery diagnosis technology is used, then the overall battery state can be diagnosed, but the negative electrode state cannot be diagnosed separately from the positive electrode state
Solution Approach 1:
The patent segments the battery diagnosis into separate positive electrode and negative electrode assessments. By generating distinct profiles for each electrode (positive electrode profile and negative electrode profile) based on voltage-capacity relationships, the system can independently evaluate the state of each electrode, thereby preventing information loss about the negative electrode while maintaining overall battery diagnosis capability.
2Quantity of substance
If an active material that undergoes phase transformation (e.g., pure silicon) is applied to the negative electrode, then the energy density and capacity are improved, but the accurate diagnosis of negative electrode degradation becomes difficult
Solution Approach 1:
The patent addresses the diagnosis difficulty of phase-transforming materials by changing the diagnostic parameters from direct capacity measurement to voltage-capacity relationship analysis. By generating negative electrode profiles that correlate voltage changes with capacity changes during charge-discharge cycles, the system can accurately assess degradation of materials like pure silicon that undergo phase transformation, enabling precise measurement despite the complex material behavior.
3Ease of operation
If the battery is diagnosed through overall SOH (State of Health), then the general battery status can be assessed, but the specific state of individual electrodes cannot be determined
Solution Approach 1:
The patent maintains diagnostic simplicity while preventing information loss by segmenting the overall battery diagnosis into electrode-specific assessments. The system generates separate positive and negative electrode profiles from the same voltage-capacity data, allowing individual electrode states to be determined without complicating the overall diagnosis process. This segmentation enables both simple operation and detailed information retention.
Data Source
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AI summary
A method for diagnosing a battery according to one aspect of the present disclosure includes: generating a battery profile representing a relationship between a capacity and a voltage of the target battery for each predetermined number of charge cycles or discharge cycles; obtaining a negative electrode profile estimating a relationship between a negative electrode capacity and a negative electrode potential of the target battery based on the battery profile; obtaining a diagnostic factor value representing an available capacity per unit area of the negative electrode based on the negative electrode profile; and diagnosing a state of the negative electrode based on diagnostic factor values sequentially obtained as the charge cycle or the discharge cycle is repeated.