Secondary Battery Electrode Design for Low Cell Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The development of secondary batteries with high output and long lifespan is hindered by the need for a long evaluation period for cycle life, which can be time-consuming, and existing methods fail to accurately predict battery performance based on electrode resistance alone.
Innovation Solution
A secondary battery design that incorporates specific relationships between adhesive force, density, and resistance parameters, represented by K1 and K2 values, to predict cycle life without extensive testing, ensuring low cell resistance and excellent lifespan characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a long evaluation period is used to assess cycle life, then the accuracy of lifespan prediction is improved, but the development time increases significantly
Solution Approach 1:
The patent performs preliminary measurements of electrode resistance and adhesive force before battery assembly and cycling tests. These preliminary actions allow prediction of cycle life without waiting for long-term evaluation, thus reducing development time while maintaining prediction accuracy
Solution Approach 2:
The patent uses electrode resistance and adhesive force measurements as proxies (copies) for the actual cycle life performance. Instead of directly measuring cycle life over long periods, these surrogate measurements correlate with lifespan outcomes, enabling rapid assessment without time-consuming long-term testing
2Device complexity
If electrode resistance alone is used for prediction, then the measurement process is simplified, but the prediction accuracy is insufficient
Solution Approach 1:
The patent combines multiple measurement parameters (electrode resistance and adhesive force) into a composite prediction model. This multi-parameter approach provides more comprehensive and accurate battery performance prediction compared to using single parameter measurements
3Use of energy by moving object
If high output and large capacity are pursued, then the energy storage capability is improved, but the cell resistance increases
Solution Approach 1:
The patent optimizes electrode parameters including resistance characteristics and adhesive force within specific ranges to achieve the desired balance between energy storage capacity and cell resistance. By controlling these parameters during electrode fabrication, the battery achieves both high capacity and low resistance
Data Source
Figure 1~2
Figure 3
AI summary
The present disclosure relates to a secondary battery having a low cell resistance and excellent lifespan characteristics. According to an exemplary embodiment, there is provided a secondary battery including: a cathode including a cathode current collector and a cathode active material layer formed on at least one surface of the cathode current collector; and an anode including an anode current collector and an anode active material layer formed on at least one surface of the anode current collector, wherein a value of K1 represented by the following Expression (1) is 130 to 270: 200*AR+CR+20*CIR*1+CA/CP in Expression (1), AR is a bulk resistance (Ω·cm) of the anode, CR is a bulk resistance (Ω·cm) of the cathode, CIR is an interfacial resistance (Ω·cm2) between the cathode active material layer and the cathode current collector, CP is 1 - D/4.7, D is a pressed density (g/cc) of the cathode, and CA is an adhesive force (N/18 mm) between the cathode active material layer and the cathode current collector.