Lithium Battery Electrolyte Additive for High Density Capacity
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Solution Overview
Problem
Lithium rechargeable batteries face challenges in achieving high capacity and improved cycle-life characteristics, particularly at room temperature, due to the trade-off between active-mass density and cycle-life performance.
Innovation Solution
Incorporating a nitrile-based compound additive, such as adiponitrile, in the non-aqueous electrolyte of lithium rechargeable batteries, which maintains high active-mass density of the positive electrode while enhancing cycle-life and capacity, by optimizing the additive's concentration within a specific range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the active-mass density of the positive electrode is increased to achieve high capacity, then the battery capacity is improved, but the cycle-life characteristics deteriorate at room temperature
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing a nitrile-based compound (specifically adiponitrile) as an additive. This chemical parameter change allows the system to maintain high capacity with 3.7 to 4.1 g/cc active-mass density positive electrodes while improving cycle-life characteristics at room temperature, resolving the trade-off between capacity and cycle-life
Solution Approach 2:
The nitrile-based compound additive acts as an intermediary substance in the electrolyte that mediates between the high active-mass density positive electrode and the overall battery performance. This intermediary enables the system to achieve both high capacity and improved cycle-life by facilitating proper electrochemical reactions and stabilizing the electrode-electrolyte interface
2Quantity of substance
If the active-mass density of the positive electrode is increased to achieve high capacity, then the battery capacity is improved, but the performance at elevated temperatures deteriorates
Solution Approach 1:
The patent modifies the electrolyte composition by adding nitrile-based compound (adiponitrile) which changes the thermal and electrochemical parameters of the system. This enables the battery to maintain both high capacity and stable performance at elevated temperatures when using high active-mass density (3.7 to 4.1 g/cc) positive electrodes
3Reliability
If the active-mass density of the positive electrode is maintained at conventional levels (around 3.6 g/cc) to ensure cycle-life, then the battery capacity is limited
Solution Approach 1:
The patent changes the electrolyte composition parameters by incorporating nitrile-based compound additive, which allows the system to突破 the conventional limitation. This enables achieving both high capacity (through increased active-mass density of 3.7 to 4.1 g/cc) and improved cycle-life characteristics simultaneously, rather than having to choose one over the other
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 nitrile-based compounds in the electrolyte allows for improved cycle-life and capacity retention even at higher active-mass densities of the positive electrode, from 3.7 to 4.1 g/cc, maintaining performance at both room and elevated temperatures.
Implementation Method 1
Lithium rechargeable batteries use an organic electrolyte solution... contain a positive active material, for example lithium-transition element composite oxides capable of intercalating lithium... contain a negative active material, for example various carbon-based materials, such as, artificial graphite, natural graphite, and hard carbon, which can all intercalate and deintercalate lithium ions
Implementation Method 2
lithium-transition element composite oxides capable of intercalating lithium... which can all intercalate and deintercalate lithium ions
Data Source
AI summary
A rechargeable lithium battery including a positive electrode including a positive active material, a negative electrode including a negative active material, and a non-aqueous electrolyte including a non-aqueous organic solvent and a lithium salt. The positive electrode has an active-mass density of about 3.7 to 4.1 g/cc, and the non-aqueous electrolyte includes a nitrile-based compound additive, a non-aqueous organic solvent, and a lithium salt.