Separator Laminate Structure for Lithium Battery Micro-Short Prevention
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Solution Overview
Problem
Lithium secondary batteries are prone to micro-short circuits due to metal columns growing through the pores of the separator, which can lead to safety hazards and reduced battery life.
Innovation Solution
A separator laminate is developed with multiple separators laminated together, each with an adhesive layer along the edges to create a separation space. This design changes the growth direction of metal columns from vertical to horizontal, inhibiting short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single separator is used in the battery, then the device complexity is low, but the reliability is poor due to micro-short circuits caused by metal column growth through separator pores
Solution Approach 1:
The separator is divided into multiple layers (first separator, second separator, third separator) with different functional characteristics. Each layer segments the prevention of metal column growth into distinct zones, where the first separator provides initial barrier, the second separator with adhesive layer redirects growth horizontally, and the third separator provides additional protection, collectively enhancing short circuit prevention without requiring a single complex separator design
Solution Approach 2:
The second separator introduces a horizontal dimension to metal column growth redirection. By positioning the adhesive layer at specific locations on the second separator, the invention transforms the vertical growth path of metal columns into a horizontal growth path, changing the dimension of growth restriction and preventing direct penetration through to the positive electrode
2Reliability
If multiple separators are laminated together to prevent micro-short circuits, then the reliability improves, but the mechanical strength and structural stability may be compromised
Solution Approach 1:
The adhesive layer serves as an intermediary component between the second separator and other separators. It provides strong bonding to ensure mechanical integrity of the multi-layer structure while simultaneously creating the horizontal growth redirection function. The adhesive layer mediates between the need for structural strength and the need for short circuit prevention, achieving both objectives
Solution Approach 2:
The adhesive layer is positioned at specific local regions of the second separator rather than covering the entire surface. This local quality approach allows the separator structure to maintain mechanical strength in non-adhesive regions while providing short circuit prevention functionality at the adhesive layer locations, optimizing the balance between strength and reliability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The separator laminate effectively prevents micro-short circuits by redirecting metal column growth, enhancing the mechanical strength of the battery, and prolonging its lifespan.
Implementation Method 1
N−1 adhesive layers positioned between the N separators, wherein the N−1 adhesive layers are respectively formed along edges of the N separators so as to have a separation space between the N separators
Implementation Method 2
the separator laminate effectively prevents micro-short circuits by redirecting metal column growth
Data Source
AI summary
The present disclosure relates to a separator for lithium secondary battery, a method for manufacturing same, and a lithium secondary battery including the same. The separator laminate according to one embodiment of the present disclosure includes: a plurality of separators; and adhesive layers located between mutually adjacent separators among the plurality of separators, wherein the adhesive layers are formed along the edges of the mutually adjacent separators so as to have a separation space between the mutually adjacent separators.