Zinc Battery Negative Electrode Composition for Longer Cycle Life
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Solution Overview
Problem
Zinc secondary batteries face shortened cycle life due to morphological changes of the negative electrode, leading to increased resistance and difficulty in charge and discharge processes, despite previous attempts to improve durability.
Innovation Solution
A negative electrode comprising ZnO particles, metallic Zn particles with a specific average particle diameter, and Bi2O3 particles with controlled average major axis diameter, which inhibits hydrogen generation and enhances cycle characteristics by preventing overcharge and self-discharge reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If zinc is repeatedly dissolved and precipitated during charge and discharge, then the negative electrode undergoes morphological changes, but this causes high resistance due to clogging of pores, decrease in charge active material, and difficulty in charge and discharge
Solution Approach 1:
The invention changes the physical and chemical parameters of the negative electrode by incorporating ZnO particles (0.1-20 μm), metallic Zn particles (85-250 μm), and Bi2O3 particles (0.3-8.5 μm) in specific proportions. This multi-component particle system modifies the electrode's morphological stability, preventing pore clogging and maintaining charge capacity during repeated cycling, thus resolving the contradiction between cycle life and charge/discharge performance
Solution Approach 2:
The invention uses a composite material system combining three types of particles (ZnO, metallic Zn, and Bi2O3) with different functions. ZnO provides structural stability, metallic Zn provides active material, and Bi2O3 suppresses hydrogen generation. This composite structure prevents morphological degradation during cycling while maintaining electrical conductivity and charge capacity, thereby improving both cycle life and reliability
2Reliability
If Bi2O3 particles are added to suppress hydrogen generation and improve cycle characteristics, then overcharge and self-discharge reactions are inhibited, but the negative electrode composition becomes more complex
Solution Approach 1:
The invention optimizes the particle size parameters of Bi2O3 (0.3-8.5 μm average major axis diameter) to achieve maximum effectiveness in suppressing hydrogen generation. By controlling the particle size within this specific range, the Bi2O3 particles can effectively inhibit overcharge and self-discharge reactions while maintaining a relatively simple three-component composition system, thus resolving the contradiction between improved reliability and composition complexity
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 use of Bi2O3 particles with a predetermined size distribution on the surface of ZnO particles in the negative electrode significantly prolongs the cycle life of zinc secondary batteries by reducing undesirable reactions and maintaining electrode durability.
Implementation Method 1
Bi2O3 particles having a predetermined average major axis diameter together with ZnO particles and Zn particles in a negative electrode, it is inhibited from being deteriorated due to repeated charge/discharge cycles
Implementation Method 2
The use of Bi2O3 particles with a predetermined size distribution on the surface of ZnO particles in the negative electrode significantly prolongs the cycle life of zinc secondary batteries by reducing undesirable reactions including overcharge
Implementation Method 3
as zinc repeatedly dissolves and precipitates due to repeated charge and discharge, the negative electrode changes its morphology
Implementation Method 4
zinc repeatedly dissolves and precipitates due to repeated charge and discharge
Implementation Method 5
metallic zinc precipitates from a negative electrode in the form of dendrites upon charging
Implementation Method 6
penetrates into voids of a separator such as a nonwoven fabric and reaches a positive electrode
Implementation Method 7
batteries comprising layered double hydroxide (LDH) separators that prevent penetration of zinc dendrites while selectively permeating hydroxide ions
Implementation Method 8
LDH separator has a high density to the degree that it has gas impermeability and/or water impermeability
Data Source
AI summary
Provided is a negative electrode for use in a zinc secondary battery, including ZnO particles, metallic Zn particles having an average particle diameter D50 of 85 to 250 μm, and Bi2O3 particles having an average major axis diameter of 0.3 to 8.5 μm, in which the content of the metallic Zn particles is 1.0 to 87.5 parts by weight and the content of the Bi2O3 particles is 0.5 to 20 parts by weight, based on the content of the ZnO particles being 100 parts by weight.