LDH Separator Erosion in Zinc Batteries
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Solution Overview
Problem
Secondary zinc batteries face issues with short circuits due to zinc dendrite penetration and degradation of layered double hydroxide (LDH) separators in alkaline electrolytic solutions, leading to reduced service life.
Innovation Solution
A battery design utilizing a layered double hydroxide-like compound with a specific composition, which is resistant to alkaline degradation, is used as a separator in contact with an aqueous alkali metal hydroxide solution, where a metal compound is dissolved to suppress erosion, ensuring high hydroxide ion conductivity and alkali resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a layered double hydroxide (LDH) separator is used to block zinc dendrites, then short circuit prevention is improved, but the separator degrades in alkaline electrolytic solution over time
Solution Approach 1:
The patent modifies the chemical composition parameters of the LDH separator by incorporating specific metal compounds (such as aluminum compounds) at controlled concentrations in the electrolytic solution. This changes the electrochemical environment to suppress the degradation reactions of the LDH structure while maintaining its dendrite-blocking function, thereby extending separator service life without compromising short circuit prevention.
2Use of energy by moving object
If conventional LDH separator is used in aqueous KOH electrolytic solution, then hydroxide ion conductivity is achieved, but erosion and degradation of the separator occurs
Solution Approach 1:
The patent introduces aluminum compounds as intermediary substances in the electrolytic solution that act as protective mediators. These aluminum compounds form protective complexes or surface layers on the LDH separator, reducing direct contact between the aggressive KOH solution and the LDH structure, thereby suppressing erosion while allowing hydroxide ion transport to continue.
3Reliability
If the electrolytic solution concentration is increased to improve ion conductivity, then hydroxide ion transport is enhanced, but degradation of the LDH separator accelerates
Solution Approach 1:
The patent creates a composite electrochemical system where the LDH separator works in conjunction with aluminum-containing compounds in the electrolyte. This composite approach allows the system to maintain high ion conductivity through the LDH structure while the aluminum compounds provide protective effects that stabilize the separator composition against degradation, even in concentrated KOH solutions.
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 solution significantly reduces the degradation of the LDH-like compound, maintaining high hydroxide ion conductivity and density over time, resulting in a highly reliable battery with improved alkali resistance and prevention of short circuits.
Implementation Method 1
layered double hydroxide (LDH) separators that selectively permeate hydroxide ions while blocking the penetration of zinc dendrites
Implementation Method 2
LDH separator that is dense enough to restrict permeation of gas and/or water
Implementation Method 3
a metal compound containing a metal corresponding to M2+ and/or M3+ is dissolved in the electrolytic solution such that erosion of the layered double hydroxide by the electrolytic solution is suppressed
Data Source
AI summary
Provided is a battery including a positive electrode; a negative electrode; an electrolytic solution being an aqueous alkali metal hydroxide solution; and a layered double hydroxide (LDH)-like compound provided so as to be in contact with the electrolytic solution. A metal compound containing at least one metal element constituting the LDH-like compound is dissolved in the electrolytic solution such that erosion of the LDH-like compound by the electrolytic solution is suppressed.