Battery SOH Estimation Using OCV Profile and Electrode Adjustment
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Solution Overview
Problem
Conventional methods for diagnosing the state of a battery require low-rate charging and discharging, which is time-consuming and limits the use of the battery, making it difficult to accurately assess the State of Health (SOH) within a reasonable timeframe.
Innovation Solution
An apparatus and method that estimates SOH using Open Circuit Voltage (OCV) profiles, adjusting positive and negative electrode profiles to determine diagnosis factors, allowing for quick and accurate estimation without the need for low-rate charging and discharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If low-rate charging and discharging is used to diagnose battery state, then measurement precision is improved, but loss of time increases significantly
Solution Approach 1:
The patent changes the measurement parameter from capacity-voltage relationship (requiring low-rate charge/discharge) to open-circuit voltage (OCV) profile analysis. By measuring OCV at different states of charge without actual charge/discharge cycles, the system achieves accurate battery state diagnosis while eliminating the time-consuming low-rate charging process. The OCV profile characteristics serve as diagnostic parameters that reflect battery health without requiring time-intensive electrical cycling.
2Measurement precision
If low-rate charging and discharging is performed, then battery state diagnosis accuracy is improved, but ease of operation deteriorates due to usage restrictions
Solution Approach 1:
The patent enables the battery system to perform self-diagnosis by analyzing its own OCV profile characteristics without requiring external low-rate charging equipment or restrictive operational conditions. The battery's natural OCV behavior at different charge levels provides sufficient information for accurate state assessment, eliminating the need for controlled charging environments and specialized testing procedures. This self-service approach maintains full operational flexibility while achieving diagnostic accuracy.
3Reliability
If conventional battery profile analysis is used, then reliability of battery state assessment is improved, but productivity decreases due to time requirements
Solution Approach 1:
The patent extracts the essential diagnostic information from the battery by analyzing only the OCV profile characteristics rather than requiring complete capacity-voltage profiles obtained through full charge/discharge cycles. By taking out and analyzing specifically the OCV data at different states of charge, the system achieves reliable battery state assessment without the time-consuming process of obtaining complete battery profiles through conventional low-rate charging and discharging methods.
Data Source
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AI summary
An apparatus for estimating a SOH according to one aspect of the present disclosure may include a profile obtaining unit configured to obtain an OCV profile for a plurality of OCVs of a battery measured at different time points; a profile correcting unit configured to generate an adjusted positive electrode profile and an adjusted negative electrode profile by adjusting a preset criterion positive electrode profile and a preset criterion negative electrode profile to correspond to the OCV profile; and a control unit configured to extract a diagnosis factor regarding a positive electrode participation initiating point for the battery from the adjusted positive electrode profile, and estimate an available lithium SOH of the battery based on the extracted diagnosis factor.