Multi-Functional Battery Separator for Zinc-Silver Oxide Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional separators for alkaline batteries decompose in alkaline electrolytes, are susceptible to chemical oxidation, and lack mechanical strength, leading to short-term resistance issues and dendrite formation, which limits battery life and efficiency.
Innovation Solution
A multi-functional battery separator is developed with a multilayered unitary structure comprising active layers deposited from different polymer solutions, using the cascade coating method to minimize physical and electrical changes during drying, and incorporating a dendrite-resistant layer facing the anode and an oxidation-resistant layer facing the cathode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional separators are used in alkaline batteries, then the battery can be manufactured with simple structure, but the separator decomposes in alkaline electrolyte and is susceptible to chemical oxidation, leading to short battery life
Solution Approach 1:
The patent applies composite materials by creating a multilayered separator structure where each layer is made from different polymer solutions with specific properties. The first layer uses a polymer resistant to chemical oxidation, the second layer uses a polymer resistant to decomposition in alkaline electrolyte, and optionally a third layer provides additional functionality. This composite approach allows the separator to simultaneously resist both oxidation and alkaline decomposition, solving the reliability problem while maintaining manufacturing feasibility through the cascade coating method.
Solution Approach 2:
The patent segments the separator into multiple functional layers, each addressing specific failure modes. Rather than using a single material that must compromise between resisting oxidation and alkaline decomposition, the separator is divided into distinct layers: a first layer resistant to oxidation, a second layer resistant to alkaline decomposition, and optionally a third layer for additional protection or functionality. This segmentation allows each layer to specialize in one protective function, thereby achieving overall superior reliability.
2Device complexity
If traditional single-layer separators are used, then the manufacturing process is simple, but the separator lacks mechanical strength and allows dendrite formation
Solution Approach 1:
The patent uses composite materials to address mechanical strength by combining polymers with different mechanical properties in a multilayered structure. Each polymer layer contributes its inherent mechanical characteristics, and the layered composite structure provides overall enhanced mechanical strength and dendrite resistance compared to single-layer separators. The cascade coating method ensures proper bonding between layers while maintaining the structural integrity needed to prevent dendrite formation.
3Adaptability or versatility
If multiple separator layers are deposited separately, then each layer can be optimized for specific function, but physical and electrical changes occur during drying that reduce performance
Solution Approach 1:
The patent applies preliminary action by depositing multiple polymer layers in a wet state using the cascade coating method before any drying occurs. This allows the layers to be positioned and configured while in their native solvent state, minimizing physical and electrical changes that would otherwise occur during subsequent drying processes. The layers are deposited sequentially from different polymer solutions, each optimized for specific functions, and the wet deposition process preserves the electrical and physical properties of the polymers, ensuring optimal performance.
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 multi-functional separator enhances ionic conductivity, reduces battery production costs, and prevents dendrite formation and oxidation, thereby improving the longevity and performance of zinc-silver oxide batteries.
Implementation Method 1
the physical, electrical and morphological changes associated with the polymer drying out process are avoided or minimized
Implementation Method 2
resist oxidation in contact with the highly oxidizing cathode
Implementation Method 3
the separator must suppress dendritic growth and/or resist dendrite penetration to avoid failure due to formation of a dendritic short between the electrodes
Implementation Method 4
a battery separator must be both an effective electrolyte transport barrier and a sufficiently good ionic conductor
Data Source
AI summary
A multi-functional battery separator comprises two or more active separator layers deposited from different polymer solutions to form a multilayered unitary structure comprising a free-standing film, a multiplex film on one side of a porous substrate, or separate films or multiplex films on opposite sides of a porous substrate. In a preferred embodiment, the cascade coating method is used to simultaneously deposit the active separator layers wet so that the physical, electrical and morphological changes associated with the polymer drying out process are avoided or minimized. The multi-functional separator is inexpensive to fabricate, exhibits enhanced ionic conductivity and ionic barrier properties, and eliminates gaps between individual layers in a separator stack that can contribute to battery failure.