Lithium-Ion Battery Electrolyte Additive for Dendrite Suppression
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Solution Overview
Problem
Existing lithium ion battery electrolytes suffer from lithium dendrite precipitation, leading to poor cycle performance and safety issues.
Innovation Solution
A preparation method involving dissolving picric acid in an organic solvent containing B, F, and N elements, followed by crystallization, to produce an electrolyte additive that forms a stable polymer layer and SEI film, inhibiting dendrite growth through electropolymerization reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electrolyte is used, then battery assembly is simple, but lithium dendrites precipitate and cycle performance deteriorates
Solution Approach 1:
The patent uses a composite electrolyte system combining conventional carbonate solvents (EC, DMC, DEC) with a novel fluorinated cyclic carbonate additive containing F, B, and N elements. This composite approach allows the base electrolyte to maintain simple assembly compatibility while the additive component provides dendrite suppression and improved cycle performance through formation of stable SEI films.
Solution Approach 2:
The patent modifies the electrolyte composition by introducing an additive with specific elemental composition (F, B, N) and molecular structure (fluorinated cyclic carbonate). This parameter change in the electrolyte's chemical composition enables the formation of a more stable solid electrolyte interface (SEI) layer, preventing lithium dendrite growth and improving cycle performance without significantly complicating the overall system.
2Object-affected harmful factors
If conventional electrolyte additive is used, then manufacturing process is simple, but lithium dendrite growth is not suppressed
Solution Approach 1:
The patent employs a preliminary action approach by pre-synthesizing the fluorinated cyclic carbonate additive with specific F, B, and N elemental composition before incorporating it into the electrolyte. This pre-prepared additive is then added to the conventional electrolyte mixture, allowing it to proactively suppress lithium dendrite growth during battery operation while maintaining relatively simple manufacturing processes through straightforward mixing and formulation.
3Stability of the object's composition
If electrolyte additive with F, B, N elements is used, then polymer layer stability improves, but additive synthesis complexity increases
Solution Approach 1:
The patent creates a composite additive structure incorporating multiple elements (F, B, N) within a fluorinated cyclic carbonate molecular framework. This composite material approach allows the additive to form highly stable polymer layers and SEI films on lithium surfaces through the synergistic effects of different elements, while the synthesis process remains manageable by building upon conventional cyclic carbonate synthesis methodologies with additional fluorination steps.
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 electrolyte additive reduces battery resistance and enhances cycle performance by forming a rigid and stable polymer layer that suppresses lithium dendrite growth, improving the battery's cycle life and safety.
Implementation Method 1
Dissolving a picric acid in an organic solvent to obtain an additive solution
Implementation Method 2
Performing crystallization from the additive solution, to precipitate the electrolyte additive
Implementation Method 3
forming a stable polymer layer and SEI film, inhibiting dendrite growth through electropolymerization reactions
Implementation Method 4
the electrolyte additive can be polymerized to form BxOy (x=n, y=n+1) when a battery is charged and discharged, and at the same time, it is beneficial for an SEI film to generate of LiF, Li3N, etc. of higher contents
Data Source
Figure 1~2
AI summary
Disclosed are an electrolyte additive and a preparation method therefor, an electrolyte and a lithium ion battery. The preparation method for an electrolyte additive comprises: dissolving a picric acid in an organic solvent to obtain an additive solution, the organic solvent comprising at least one element of B, F and N; and performing crystallization from the additive solution, to precipitate an electrolyte additive. The electrolyte additive helps to make a polymer layer and an SEI film more rigid and stable, and helps to suppress the growth of lithium dendrites. The electrolyte added with the electrolyte additive can reduce the resistance of a lithium ion battery, and further improving the cycle performance of the lithium ion battery. The lithium ion battery provided in the present disclosure comprises the electrolyte added with the electrolyte additive, and therefore has a lower resistance and better cycle performance.