Zn-Oxide Coated MnO2 Cathode for High-Temperature Storage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium primary batteries experience significant performance degradation, including increased resistance and reduced pulse discharge performance, when stored at high temperatures.
Innovation Solution
A positive electrode active material composed of LixMnO2 particles with a zinc-containing oxide coverage ranging from 0.10% to 65% covers the surface of the particles, and a non-aqueous electrolyte containing a cyclic imide compound is used to suppress performance degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the positive electrode active material is stored at high temperature, then the battery provides high energy density and low self-discharge, but the resistance increases significantly and pulse discharge performance reduces
Solution Approach 1:
The patent applies local quality by selectively coating only the surface of the manganese dioxide particles with zinc-containing oxide. This creates a localized protective layer on the particle surfaces that prevents harmful high-temperature reactions while maintaining the bulk properties of the active material. The coating coverage is controlled at 5-50% of the particle surface area, providing localized protection without excessive material addition.
Solution Approach 2:
The patent creates a composite material structure by combining manganese dioxide particles with zinc-containing oxide coating. This composite structure integrates the high energy density properties of MnO2 with the thermal stability and protective properties of zinc oxide, forming a new material system that exhibits both high performance and resistance to high-temperature degradation.
2Reliability
If metal oxide is dispersed between manganese dioxide particles to improve performance, then the positive electrode structure becomes more complex, but the production process becomes more difficult
Solution Approach 1:
The patent merges the coating process with the existing production workflow by applying zinc-containing oxide to manganese dioxide particles during the electrode fabrication process. This integration combines multiple functions (protection, performance enhancement) into a single manufacturing step, avoiding the need for separate complex processing stages.
Solution Approach 2:
The patent optimizes the coating coverage parameter to fall within 5-50% of the particle surface area. This parameter optimization balances performance improvement with manufacturing ease, ensuring sufficient protection without creating excessive complexity in the production process. The controlled coverage range allows for scalable manufacturing.
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 solution effectively reduces performance degradation due to high-temperature storage by minimizing internal resistance and gas generation, maintaining discharge capacity and pulse discharge performance.
Implementation Method 1
a zinc-containing oxide partially covering surfaces of the active material particles, wherein a coverage of the active material particles by the zinc-containing oxide is in a range from 0.10% to 65%
Data Source
AI summary
Disclosed is a positive electrode active material for a lithium primary battery, including: active material particles represented by a composition formula LixMnO2 where 0≤x≤0.05; and a zinc-containing oxide partially covering surfaces of the active material particles. The coverage of the active material particles by the zinc-containing oxide is in the range from 0.10% to 65%.