Zinc Secondary Battery LDH Separator and Pressuring Unit
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Solution Overview
Problem
Secondary zinc batteries face short-circuiting issues due to zinc dendrite growth, which reduces their charge and discharge repetition lifetime, and existing solutions with layered double hydroxide (LDH) separators have gaps that allow dendrite propagation.
Innovation Solution
A secondary zinc battery configuration with a polymeric porous substrate LDH separator and a pressuring unit that compacts the unit cell to minimize gaps between the negative electrode and the LDH separator, ensuring close contact and preventing zinc dendrite growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If gaps are left between negative electrode and LDH separator filled with electrolytic solution, then ease of assembly is improved, but zinc dendrite propagation is enabled causing short circuiting
Solution Approach 1:
The LDH separator is pre-formed with an adhesive layer on its surface before battery assembly. This preliminary preparation enables the separator to immediately bond with the negative electrode upon assembly, eliminating gaps without requiring additional assembly steps or adjustments, thus maintaining ease of manufacture while preventing dendrite propagation
Solution Approach 2:
An adhesive layer is introduced as an intermediary substance between the LDH separator and the negative electrode. This adhesive mediator enables reliable bonding and gap elimination while simplifying the assembly process, as the adhesive properties facilitate automatic bonding upon contact without requiring complex assembly mechanisms
2Reliability
If LDH separator is made dense to block zinc dendrites, then short circuit prevention is improved, but hydroxide ion conductivity is reduced
Solution Approach 1:
The LDH separator is constructed as a composite material combining layered double hydroxide with a porous substrate structure. The LDH provides dendrite-blocking capability while the porous substrate maintains ion conductivity pathways, achieving both short circuit prevention and adequate hydroxide ion transport simultaneously
Solution Approach 2:
The LDH separator exhibits different local properties: the LDH crystalline regions provide dense dendrite blocking, while the porous substrate regions provide ion conduction channels. This spatial differentiation of properties allows the separator to simultaneously block zinc dendrites and conduct hydroxide ions effectively
3Reliability
If pressuring unit is added to compact unit cell, then zinc dendrite growth is prevented, but device complexity increases
Solution Approach 1:
The pressuring function is merged with the battery's existing structural components, such as integrating the pressing mechanism into the cell housing or using the assembly process itself to apply sufficient compression. This combines multiple functions into existing structures, preventing dendrite growth without adding separate complex pressuring devices
Solution Approach 2:
The adhesive layer between the LDH separator and negative electrode provides self-sustaining bonding that maintains continuous contact and compression without requiring external pressuring mechanisms. The adhesive force itself serves the pressuring function, eliminating the need for additional complex pressuring units
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
This configuration effectively blocks zinc dendrite propagation, improving battery performance by reducing cell resistance and facilitating assembly, while maintaining the benefits of hydroxide-ion conductivity and gas-impermeability.
Implementation Method 1
a layered double hydroxide (LDH) separator comprising a porous substrate composed of a polymeric material and LDH, pores of the porous substrate being filled with the LDH such that the LDH separator is hydroxide-ion-conductive
Implementation Method 2
a pressuring unit compacting the unit cell to bring the negative-electrode structure in close contact with the LDH separator
Implementation Method 3
the LDH separator separating the positive electrode from the negative-electrode active material layer
Data Source
AI summary
There is provided a secondary zinc battery including: (a) at least one unit cell including; a positive electrode; a negative-electrode structure including a negative-electrode active material layer containing at least one selected from the group consisting of elemental zinc, zinc oxide, zinc alloys, and zinc compounds; a LDH separator including a porous substrate composed of a polymeric material and layered double hydroxide (LDH); and an electrolytic solution; and (b) a pressuring unit compacting the unit cell to bring the negative-electrode structure in close contact with the LDH separator. Pores of the porous substrate are filled with the LDH such that the LDH separator is hydroxide-ion-conductive and gas-impermeable. The LDH separator separates the positive electrode from the negative-electrode active material layer.