Button Battery Carbon Foil Structure for Low-Temperature Discharge
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Solution Overview
Problem
Lithium manganese dioxide batteries face issues with high internal resistance due to reactions between the negative electrode and electrolyte components, leading to reduced discharge characteristics, especially at low temperatures.
Innovation Solution
A button battery design incorporating a carbon foil between the negative electrode sheet and the separator, which acts as a self-supporting carbon layer to suppress reactions and reduce internal resistance, thereby enhancing high-current discharge and low-temperature pulse performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a non-aqueous electrolyte is used in lithium manganese dioxide battery, then the battery can operate at low temperatures, but the negative electrode surface reacts with electrolyte components generating high-resistance coating films that increase internal resistance
Solution Approach 1:
A carbon coating layer is applied as an intermediary between the negative electrode (lithium sheet) and the non-aqueous electrolyte. This carbon layer mediates the interaction by providing a stable interface that prevents direct reaction between lithium and electrolyte components, thereby eliminating the formation of high-resistance coating films while maintaining low-temperature operation capability.
Solution Approach 2:
The carbon coating layer is applied in advance to the negative electrode surface before battery operation. This preliminary protective action prevents the harmful reaction between lithium and electrolyte from occurring in the first place, stopping the formation of high-resistance products before they can increase internal resistance.
2Power
If manganese ions are generated from positive active material dissolution, then the battery can maintain discharge capacity, but these ions react with negative lithium sheet to form high-impedance components that reduce discharge characteristics
Solution Approach 1:
The carbon coating layer serves as a mediator that allows manganese ions to be present in the electrolyte (maintaining discharge capacity) while preventing these ions from reacting with the negative lithium sheet. The carbon layer acts as a selective barrier that maintains ionic conductivity for capacity while blocking the formation of high-impedance components.
3Quantity of substance
If the battery is stored in a certain degree of discharge, then capacity is retained, but a large number of high-resistance elements are generated on the negative electrode surface significantly reducing discharge characteristics
Solution Approach 1:
The carbon coating layer provides preliminary protection to the negative electrode surface, preventing the generation of high-resistance elements during storage at discharged states. By maintaining a stable carbon interface, the harmful reactions that would otherwise occur during storage are suppressed, preserving discharge characteristics even when capacity is retained.
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 carbon foil reduces the internal resistance of the battery and the negative electrode surface, significantly improving the battery's high-current discharge and pulse performance at low temperatures.
Implementation Method 1
the carbon foil and its function as a self-supporting carbon layer to suppress reactions
Data Source
AI summary
A button battery, a manufacturing method thereof, and an electronic device are disclosed, the button battery includes a housing including a bottom cover on a side of a negative electrode sheet and a positive electrode cover on a side of a positive electrode sheet; the housing includes the positive electrode sheet, a separator, a carbon foil, and the negative electrode sheet stacked in sequence; the separator has an inverted U-shape, and both sides of the inverted U-shape are bent toward the positive electrode sheet; the button battery is filled with electrolyte. The button battery of the present application is provided with the carbon foil between the negative electrode sheet and the separator.