Zinc Secondary Battery Separator Coating for Cycle Capacity Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Zinc secondary batteries experience a reduction in charge-discharge capacity due to zinc oxide segregation during repeated charge-discharge cycles, primarily caused by uneven distribution of zincate anions in the electrolyte solution.
Innovation Solution
Incorporating a covering film-attached porous film layer with a porous covering film comprising specific metal compounds like Mg(OH)2, Mg2P2O7, MgTiO3, etc., directly adjacent to the negative electrode layer to inhibit zincate anion diffusion and zinc oxide segregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional separator is used in a zinc secondary battery, then the battery can operate, but zinc oxide segregation occurs during repeated charge-discharge cycles, leading to reduced charge-discharge capacity
Solution Approach 1:
A covering film layer is introduced as an intermediary component between the negative electrode and the separator. This covering film acts as a mediator that prevents direct contact between zincate anions and the separator, thereby inhibiting zinc oxide segregation while maintaining ionic conductivity for battery operation
Solution Approach 2:
The separator structure is transformed into a composite material system consisting of the original separator combined with a covering film layer. This composite structure integrates the functions of both the separator (ionic conductivity) and the covering film (zinc oxide segregation prevention), resolving the contradiction between maintaining battery operation and preventing capacity loss
2Quantity of substance
If zincate anions are allowed to diffuse freely in the electrolyte solution, then ionic conductivity is maintained, but uneven distribution of zincate anions causes zinc oxide segregation
Solution Approach 1:
The covering film is applied locally at the negative electrode surface where zincate anion accumulation occurs. This local modification creates a zone of controlled ionic transport near the electrode while maintaining bulk electrolyte conductivity, achieving both ionic conductivity and uniform zincate anion distribution
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 enhances the cycle characteristics of zinc secondary batteries by preventing zinc oxide segregation, thereby maintaining charge-discharge capacity over repeated cycles.
Implementation Method 1
the porous covering film comprises at least one compound selected from the group consisting of Mg(OH)2, Mg2P2O7, MgTiO3, MgCO3, Ca(OH)2, CaSO4, Ca2P2O7, SrTiO3, SrF2, TiO2, SnO2, Zr(OH)4 and ZrO2
Data Source
AI summary
The present disclosure provides a zinc secondary battery with an improved cycle characteristic. The zinc secondary battery of the disclosure has a positive electrode layer, a covering film-attached porous film layer and a negative electrode layer in that order, with an electrolyte solution impregnating the positive electrode layer, the covering film-attached porous film layer and the negative electrode layer, wherein the covering film-attached porous film layer has a porous film layer and a porous covering film formed on the porous film layer, the covering film-attached porous film layer is directly adjacent to the negative electrode layer, and the porous covering film comprises at least one compound selected from the group consisting of Mg(OH)2, Mg2P2O7, MgTiO3, MgCO3, Ca(OH)2, CaSO4, Ca2P2O7, SrTiO3, SrF2, TiO2, SnO2, Zr(OH)4 and ZrO2.