Non-Aqueous Electrolyte Additives for Battery Shelf-Life at Low Temperatures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-rechargeable batteries used in applications like unmanned vehicles and space exploration suffer from performance deterioration due to degradation of active materials, electrolyte dry-up, and reactions such as oxidation of the Li anode, leading to issues like increased impedance, voltage drop, and battery failure, especially during long-term storage and low temperatures.
Innovation Solution
Incorporating a non-aqueous electrolyte with a combination of lithium nitrate and tris-trimethyl silyl phosphite additives in batteries with a fluorinated carbon material and manganese dioxide cathode, along with lithium perchlorate in organic solvents like propylene carbonate and dimethyl carbonate, enhances battery shelf-life and low temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional non-aqueous electrolytes are used in CFx/MnO2 hybrid primary batteries, then the battery can deliver power at low temperatures, but the battery performance deteriorates due to degradation of active materials, electrolyte dry-up, and oxidation reactions during long-term storage
Solution Approach 1:
The patent introduces an intermediary substance (additive) into the electrolyte that mediates between the conflicting requirements of low-temperature performance and long-term stability. The additive acts as a protective intermediary that forms a stable interface layer, preventing direct harmful interactions between the electrode materials and electrolyte while maintaining ionic conductivity for low-temperature operation
Solution Approach 2:
The patent creates a composite electrolyte system by combining conventional non-aqueous electrolyte components with specific additives (such as lithium nitrate and phosphite compounds). This composite electrolyte formulation integrates the beneficial properties of each component: the base electrolyte provides low-temperature ionic conductivity while the additive components provide long-term storage stability by suppressing degradation reactions
2Loss of time
If the battery is stored at high temperatures to simulate long-term aging, then shelf-life can be acceleratedly tested, but performance deterioration occurs due to active material degradation and electrolyte dry-up
Solution Approach 1:
The patent applies beforehand cushioning by incorporating stabilizing additives into the electrolyte formulation before storage. These additives preemptively form protective layers and suppress degradation mechanisms that would otherwise be accelerated by high-temperature storage, thereby cushioning against the harmful effects of thermal aging and enabling more accurate long-term shelf-life prediction
3Quantity of substance
If certain active species like low oxidation state Mn, moisture-free fluorine, or acid moieties are present in the Li-CFx/MnO2 system, then the battery can achieve high energy density, but these species accelerate battery self-discharge during storage
Solution Approach 1:
The patent converts the harmful effect of active species (low oxidation state Mn, moisture-free fluorine, acid moieties) by introducing additives that transform these potentially destabilizing components into beneficial elements. The additives selectively interact with these active species to form stable complexes or surface modifications, thereby converting their high reactivity from a source of self-discharge into a stabilized interface that maintains energy density while preventing unwanted side reactions
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 synergistic effect of lithium nitrate and tris-trimethyl silyl phosphite additives significantly improves battery shelf-life and maintains consistent performance over time, reducing impedance and extending discharge voltage, even at low temperatures.
Implementation Method 1
the use of electrolyte additives is an effective method as they can scavenge the unwanted species in the system and/or form a desired solid electrolyte interphase
Implementation Method 2
a non-aqueous electrolyte including: an organic solvent, one or more lithium salts including lithium perchlorate, and an additive material having lithium nitrate and tris-trimethyl silyl phosphite
Implementation Method 3
Other reactions such as oxidation of the Li anode, Li plating etc., may also contribute to the CFx/MnO2 battery degradation mechanism
Data Source
AI summary
Certain aspects of the present disclosure may include a battery including a cathode including a fluorinated carbon material and manganese oxide, an anode including one or more of a lithium metal or a lithium alloy, and a non-aqueous electrolyte including: an organic solvent, one or more lithium salts including lithium perchlorate, and an additive material having lithium nitrate and tris-trimethyl silyl phosphite.