Zinc Secondary Battery Negative Electrode Microstructure Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Zinc secondary batteries face shortening of cycle life due to morphological changes of the negative electrode, including clogging of pores and increased resistance, caused by the repeated dissolution and precipitation of zinc, leading to short circuits and reduced battery performance.
Innovation Solution
A negative electrode composition comprising ZnO particles combined with metallic Zn particles of specific sizes, In or Bi metal elements, and a binder resin with hydroxyl groups, which inhibits deterioration and maintains microstructure integrity, thereby enhancing durability and cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If zinc is used as negative electrode active material, then battery capacity is achieved, but morphological changes occur during charge/discharge cycles causing pore clogging and increased resistance
Solution Approach 1:
The patent uses a composite material system consisting of ZnO particles combined with metallic Zn particles, In or Bi metal elements, and binder resin. This composite structure prevents micromorphological changes during charge/discharge cycles while maintaining battery capacity, thereby resolving the contradiction between achieving battery capacity and maintaining microstructure stability over multiple cycles.
Solution Approach 2:
The patent specifies precise parameter ranges: metallic Zn particle size D50 of 5 to 80 μm, In content of 2.4 parts by weight or less, Bi content of 0.6 parts by weight or less, and binder resin content of 0.05 parts by weight or less. By optimizing these parameters, the negative electrode maintains its microstructure during repeated charge/discharge cycles, preventing pore clogging and resistance increase.
2Productivity
If zinc dendrites precipitate during charging, then battery operation is enabled, but dendrites penetrate separator and cause short-circuiting
Solution Approach 1:
The patent introduces In or Bi metal elements as intermediary substances that modify the precipitation behavior of zinc during charging. These intermediaries prevent the formation of sharp dendritic structures by promoting more uniform zinc deposition, thereby enabling charge/discharge capability while preventing separator penetration.
Solution Approach 2:
The patent employs a porous negative electrode structure with controlled morphology that allows zinc precipitation during charging while preventing dendrite formation. The porous structure accommodates zinc deposition in a controlled manner, maintaining charge/discharge capability while preventing harmful dendrite penetration through the separator.
3Duration of action of moving object
If repeated charge/discharge cycles are performed, then battery usage is enabled, but negative electrode morphology deteriorates causing zinc isolation
Solution Approach 1:
The patent incorporates ZnO particles and metallic Zn particles in specific ratios before battery operation begins. This preliminary composition design prevents morphological deterioration during subsequent charge/discharge cycles by maintaining a stable microstructure that accommodates zinc dissolution and precipitation without causing electrode disintegration or zinc isolation.
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 proposed negative electrode composition significantly prolongs the cycle life of zinc secondary batteries by preventing micromorphological changes, maintaining electrolyte permeation, and reducing resistance, allowing for 1.5 to 3 times more charge/discharge cycles compared to conventional designs.
Implementation Method 1
metallic zinc precipitates from a negative electrode in the form of dendrites upon charging, and penetrates into voids of a separator
Implementation Method 2
as zinc repeatedly dissolves and precipitates by repetition of charge and discharge, the negative electrode changes its morphology
Implementation Method 3
LDH separators that prevent penetration of zinc dendrites while selectively permeating hydroxide ions
Data Source
AI summary
Provided is a negative electrode for use in a zinc secondary battery containing (A) ZnO particles and (B) at least two selected from the group consisting of (i) metallic Zn particles having an average particle size D50 of 5 to 80 μm, (ii) at least one metal element selected from In and Bi, and (iii) a binder resin having a hydroxyl group.