NiMH Negative Electrode Sheet Structure for Winding Tightness Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing nickel-metal hydride batteries face challenges in controlling the tightness of their electrode assemblies, leading to deformation and internal cracking that affect electrochemical performance. Additionally, existing solutions require additional structures on the steel shell or cap, reducing energy density and increasing assembly and processing costs.
Innovation Solution
A negative electrode sheet with a substrate assembly featuring a first-ring exposed segment, a middle-ring covered segment, and a tail-ring exposed segment, along with an active layer assembly comprising first and second active layers. The active layers are strategically positioned and shaped to buffer volume and relieve stress during winding, ensuring effective control of the electrode assembly's tightness without additional structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If additional structures (fixing device or elastic piece) are added to control electrode assembly tightness, then electrode assembly tightness control is improved, but energy density is reduced and assembling/processing costs are increased
Solution Approach 1:
The invention extracts the tightness control function from external additional structures (fixing devices or elastic pieces) and integrates it into the negative electrode sheet itself through the buffer layer. This eliminates the need for separate tightness control components, thereby maintaining energy density without sacrificing tightness control capability.
Solution Approach 2:
The negative electrode sheet becomes self-sufficient by incorporating the buffer layer that automatically provides tightness control during battery assembly and operation. The buffer layer self-adjusts to maintain proper electrode assembly tightness without requiring external fixing devices or elastic pieces, reducing overall device complexity and cost.
2Manufacturing precision
If additional structures (fixing device or elastic piece) are added to control electrode assembly tightness, then electrode assembly tightness control is improved, but assembling and processing costs are increased
Solution Approach 1:
The invention merges the tightness control function with the negative electrode sheet structure by adding the buffer layer. This consolidation eliminates the need for separate fixing devices or elastic pieces, simplifying the overall battery structure and reducing assembling and processing costs while maintaining effective tightness control.
Solution Approach 2:
The invention removes the requirement for external tightness control structures (fixing devices or elastic pieces) by extracting the tightness control function and embedding it within the negative electrode sheet's buffer layer, thereby reducing device complexity and associated costs.
3Device complexity
If electrode assembly tightness is not controlled, then device complexity is reduced, but electrochemical performance deteriorates due to deformation and internal cracking
Solution Approach 1:
The buffer layer is pre-integrated into the negative electrode sheet structure to provide preliminary tightness control during the winding and assembly process. This preliminary action prevents deformation and internal cracking before they occur, ensuring electrochemical performance without requiring complex additional tightness control structures.
Solution Approach 2:
The buffer layer acts as a pre-positioned cushioning element within the negative electrode sheet that compensates for volume changes and maintains tightness control during battery assembly and operation. This beforehand cushioning prevents deformation and internal cracking, ensuring reliability without increasing device complexity.
Data Source
AI summary
Provided is a method for preparing a negative electrode sheet of nickel-metal hydride battery. The method includes steps of: obtaining a substrate roll; unwinding the substrate roll to unroll the substrate roll to form a substrate assembly (100), the substrate assembly (100) having a first-ring exposed segment (110), a middle-ring covered segment (120) and a tail-ring exposed segment (130) which are sequentially connected; and performing a slurry pulling treatment on the substrate assembly (100) to form a first active layer (210) and a second active layer (220) that are formed together on two opposite side faces of the substrate assembly (100), the first active layer (210) being attached to the first-ring exposed segment (110) and the middle-ring covered segment (120), and the second active layer (220) being attached to the middle-ring covered segment (120) and the tail-ring exposed segment (130).