Positive Electrode Additive Composition for Low-Oxygen Lithium Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium secondary batteries face issues with structural instability and excessive oxygen gas generation due to irreversible positive electrode additives, leading to decreased performance and safety, especially during high-temperature storage.
Innovation Solution
A lithium secondary battery design incorporating a positive electrode with a specific additive (LipCo(1-q)M1qO4) that adjusts the charge-to-discharge capacity ratio and has a tetragonal structure, reducing oxygen gas generation and improving operating voltage and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional irreversible additives (Li2NiO2, Li6CoO4) are used to supplement lithium ions, then battery capacity is improved, but oxygen gas generation increases causing volume expansion and performance decrease
Solution Approach 1:
The patent changes the chemical composition parameters of the irreversible additive by introducing multiple dopant elements (M1, M2, M3) into the Li6CoO4 structure. The dopants are selected from specific groups (transition metals, rare earth metals, alkaline earth metals) with controlled concentration ranges (0.1-0.5 mol each), which modifies the crystal structure stability and reduces oxygen evolution while maintaining lithium ion supplementation capability.
Solution Approach 2:
The patent creates a composite irreversible additive material with a complex multi-element structure (Li6-co-doped-Co-O4) combining cobalt oxide framework with multiple dopant elements. This composite structure leverages the synergistic effects of different elements to enhance structural stability and suppress oxygen gas generation while preserving the lithium ion supplementation function.
2Power
If irreversible additives are used to achieve high operating voltage, then battery energy density is improved, but structural instability increases leading to oxygen release and safety issues
Solution Approach 1:
The patent modifies the structural parameters of the irreversible additive by controlling the dopant concentrations (M1: 0.1-0.5 mol, M2: 0.1-0.5 mol, M3: 0.1-0.5 mol) and their specific types, which stabilizes the crystal structure at high operating voltages while maintaining the desired electrochemical performance.
Solution Approach 2:
The dopant elements act as intermediary atoms within the Li6CoO4 crystal structure, mediating between the structural stability requirement and the high voltage operation requirement. These intermediary elements reinforce the crystal lattice and prevent oxygen release while allowing the material to function as an effective irreversible additive.
3Quantity of substance
If conventional irreversible additives are stored at high temperature (60°C or more), then battery operational capacity is maintained, but self-discharging increases due to thermal instability and additional oxygen release
Solution Approach 1:
The patent changes the thermal stability parameters of the irreversible additive through multi-element doping, which suppresses thermally-induced structural transformations and oxygen release at elevated temperatures (60°C or more), thereby reducing self-discharging while maintaining operational capacity.
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 battery effectively reduces oxygen gas generation and self-discharging, enhancing operating voltage and safety, making it suitable for mid-to-large devices like electric vehicles.
Implementation Method 1
the ratio (CC/DC) of initial charge capacity (CC) to initial discharge capacity (DC) during initial charging/discharging of 50 to 100
Implementation Method 2
the positive electrode additive has a tetragonal structure with a space group of P42/nmc... reducing oxygen gas generation
Data Source
AI summary
A lithium secondary battery and a method of manufacturing the lithium secondary battery are provided. In the lithium secondary battery, a positive electrode additive represented by Formula 1 as an irreversible additive is included in a positive electrode mixture layer, and a ratio (CC/DC) of an initial charge capacity (CC) to an initial discharge capacity (DC) is adjusted within a specific range, thereby reducing the amount of oxygen gas generated in the charging/discharging of the lithium secondary battery, and at the same time, inhibiting self-discharging and improving an operating voltage by improving the open circuit voltage of the battery in initial activation and/or subsequent high-temperature storage. The lithium secondary battery including the same can be effectively used as a power source for mid-to-large devices such as electric vehicles.