Spliced Lithium Strip for Wide Electrode Pre-lithiation
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Solution Overview
Problem
Current lithium strips with small widths fail to meet the requirements for pre-lithiation of wide electrodes, leading to poor thickness uniformity and reduced production efficiency, which affects the cycle performance of lithium ion batteries.
Innovation Solution
A spliced lithium strip is created by combining two or more narrow-width lithium strips, with controlled thickness fluctuations and splicing areas to achieve a larger width and improved uniformity, enhancing pre-lithiation uniformity and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the width of the metallic lithium strip is directly increased to meet the requirements for wide electrodes, then the width requirement is satisfied, but the thickness uniformity in the transverse direction deteriorates
Solution Approach 1:
The wide lithium strip is segmented into multiple narrow-width base lithium strips that are spliced together. Each base strip maintains good thickness uniformity independently, while their combination achieves the required wide width. This segmentation approach resolves the contradiction by allowing each segment to be manufactured with precise thickness control while the overall structure provides the needed width.
2Area of stationary object
If a wide-width lithium strip is prepared by one-time molding method, then the width requirement is met, but production efficiency deteriorates due to accumulation and discontinuous production
Solution Approach 1:
The production process is segmented into manufacturing multiple narrow base strips that can be produced continuously and independently, then spliced together to form the wide strip. This enables continuous production without accumulation, as each base strip can be manufactured separately and assembled systematically, resolving the productivity issue.
Solution Approach 2:
Multiple narrow base lithium strips are prepared in advance through continuous production before splicing. This preliminary preparation allows for efficient assembly of the final wide strip without interrupting the production flow, thereby maintaining high productivity while achieving the required width.
3Area of stationary object
If a wide-width lithium strip with poor thickness uniformity is used for pre-lithiation, then the width requirement is met, but pre-lithiation uniformity deteriorates, affecting cycle performance
Solution Approach 1:
The wide lithium strip is divided into multiple narrow base strips, each with excellent thickness uniformity. When these uniformly thick base strips are spliced together, the overall pre-lithiation uniformity is maintained across the wide area, ensuring consistent cycle performance while meeting the width requirement.
Data Source
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AI summary
The present application provide a spliced lithium strip, preparation method thereof, and related negative electrode plate, battery core, lithium ion battery, battery module, battery pack and apparatus. The spliced lithium strip is formed by splicing two or more base lithium strips, wherein the base lithium strip has a thickness fluctuation of less than 5%; the spliced lithium strip has a spliced area and a non-spliced area alternately distributed along the splicing direction, and the spliced area has a maximum thickness H and the non-spliced area has a minimum thickness L, satisfying H−LL×100%≤6%.