Lithium Replenishment Assembly With Low Post-Delithiation Resistivity
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Solution Overview
Problem
Existing lithium replenishment techniques for batteries face issues with high resistivity after delithiation, affecting electron transport efficiency and energy density, and require additional conductive layers that increase cost and reduce performance.
Innovation Solution
A lithium replenishment assembly with a lithium replenishment layer on a current collector maintains low resistivity after delithiation, facilitating electron conductivity and ion transport, thereby enhancing energy density and rate performance without the need for additional conductive layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate lithium replenishment layer is provided in the positive electrode, then the lithium replenishment effect is improved, but the resistivity after delithiation increases, affecting electron transport efficiency
Solution Approach 1:
The patent applies composite materials by combining the lithium replenishment layer with a conductive carbon layer to form a composite structure. This composite material approach allows the lithium replenishment layer to provide lithium ions while the conductive carbon layer compensates for the high resistivity issue, maintaining electron transport efficiency after delithiation.
Solution Approach 2:
The conductive carbon layer acts as an intermediary between the lithium replenishment layer and the current collector. It mediates the electron transport function, allowing the lithium replenishment layer to focus on lithium ion supply while the carbon layer ensures electrical conductivity, thus resolving the resistivity problem.
2Manufacturing precision
If a conductive carbon layer is applied on the surface of the current collector to improve electronic conductivity, then the electron transport efficiency is improved, but the cost increases and energy density decreases
Solution Approach 1:
The patent merges the conductive carbon layer with the lithium replenishment layer into a single integrated layer, rather than applying them as separate layers. This merging reduces the total amount of carbon material needed while still achieving the required conductivity, thereby preserving energy density and reducing cost.
Solution Approach 2:
The combined layer serves multiple functions simultaneously: it provides lithium ion replenishment, maintains electronic conductivity, and reduces overall material usage. This multi-functionality eliminates the need for separate dedicated conductive layers, improving energy density while maintaining conductivity.
3Manufacturing precision
If a conductive carbon layer is applied on the surface of the current collector to improve electronic conductivity, then the electron transport efficiency is improved, but the device complexity and cost increase
Solution Approach 1:
The patent combines the conductive carbon layer and lithium replenishment layer into a single integrated layer, reducing structural complexity. Instead of manufacturing and assembling two separate layers, the combined structure simplifies the manufacturing process and reduces device complexity while maintaining electron transport efficiency.
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 lithium replenishment assembly achieves high energy density, long cycle life, and good rate performance by maintaining low resistivity and reducing internal resistance, while eliminating the need for additional conductive layers, thus improving battery performance and cost-effectiveness.
Implementation Method 1
the resistivity of the lithium replenishment assembly at the room temperature ranges from 2 Ω·m to 2000 Ω·m. The lithium replenishment assembly still has good electron conductivity after delithiation
Implementation Method 2
ion transport is facilitated, thereby supporting sufficient exertion of the performance, particularly the rate performance, of the electrode sheet during the charging and discharging cycle of the battery
Data Source
AI summary
The present disclosure provides a lithium replenishment assembly, a positive electrode, a secondary battery, and an electric device. The lithium replenishment assembly includes a current collector and a lithium replenishment layer provided on at least one side surface of the current collector. After delithiation of the lithium replenishment layer, the resistivity of the lithium replenishment assembly at the room temperature ranges from 2 Ω·m to 2000 Ω·m. It has a lithium replenishment effect and maintains low resistivity after delithiation of the lithium replenishment layer, thereby increasing the energy density of the battery while enabling good rate performance of the battery.