Li2CuO2 Cathode Additive for Lithium Battery Capacity and Over-discharge Protection
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Solution Overview
Problem
Conventional lithium secondary batteries suffer from unbalanced irreversible reactions between the cathode and anode, leading to over-discharge and reduced capacity, which degrades battery performance and lifespan.
Innovation Solution
Adding Li2CuO2 as a cathode additive to balance the irreversible reaction, providing lithium ions to compensate for the anode's irreversible capacity and prevent excessive electric potential increases, thereby enhancing battery capacity and preventing over-discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Li2CuO2 is added to the cathode to increase battery capacity, then the capacity increases, but the cost increases excessively
Solution Approach 1:
The patent optimizes the content parameter of Li2CuO2 in the cathode, specifying it should be 1-30 wt% of the total cathode material. This parameter optimization allows the battery to achieve increased capacity while controlling manufacturing costs by avoiding excessive use of the expensive Li2CuO2 additive.
Solution Approach 2:
The patent creates a composite cathode material consisting of Li2CuO2 combined with other cathode materials (such as LiCoO2, LiMn2O4, or LiFePO4). This composite approach allows the battery to benefit from the high capacity of Li2CuO2 while diluting its cost impact through combination with more economical materials.
2Quantity of substance
If Li2CuO2 is added to the cathode to increase capacity, then the capacity increases, but the cathode uses excessive Li2CuO2
Solution Approach 1:
The patent specifies that Li2CuO2 content should be 1-30 wt% of the total cathode material, with preferred ranges of 5-20 wt% or 10-15 wt%. This parameter optimization ensures sufficient capacity enhancement while preventing excessive consumption of Li2CuO2 that would occur with higher concentrations.
Solution Approach 2:
The patent applies partial action by using a controlled, limited amount of Li2CuO2 (1-30 wt%) rather than excessive amounts. This partial addition is sufficient to achieve the desired capacity increase and balance irreversible reactions without the need for excessive Li2CuO2 content.
3Reliability
If the battery operates in normal potential range (2.75-4.2V), then the battery functions normally, but the anode electric potential rises excessively during over-discharge
Solution Approach 1:
The patent applies preliminary anti-action by adding Li2CuO2 to the cathode before over-discharge can occur. This additive pre-balances the irreversible capacity between cathode and anode, creating a counterbalancing effect that prevents the anode potential from rising excessively when over-discharge conditions arise, thus protecting against copper foil dissolution.
Solution Approach 2:
The patent uses a composite cathode material containing Li2CuO2 combined with other cathode materials. This composite structure provides both the stability needed for normal operation (2.75-4.2V range) and the additional lithium ion capacity needed to prevent anode potential surge during over-discharge conditions.
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 addition of Li2CuO2 to the cathode increases battery capacity while preventing over-discharge, maintaining performance and restoring capacity after over-discharge, thus extending the battery's lifespan.
Implementation Method 1
a positive electrode capable of intercalating/deintercalating lithium ions, and Li2CuO2
Implementation Method 2
the unbalance of the irreversible reaction between a cathode and an anode
Implementation Method 3
the electric potential of the anode to rise excessively
Data Source
Figure 1(a)~1(b)
Figure 2~3
Figure 4(a)~4(b)
AI summary
Disclosed are an electrode including Li2CuO2 as an additive, and a lithium secondary battery having the same. The additive is added to a cathode as to adjust unbalance of the irreversible reaction between the cathode and an anode of the lithium secondary battery, thereby increasing the capacity of the lithium secondary battery without degrading performance of the lithium secondary battery after over- discharge of the lithium secondary battery.