Coffee Ground Silicon Anode Composition for Volume Expansion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Silicon anode active materials in lithium secondary batteries face issues such as volume expansion, leading to performance degradation, peeling of conductive paths, and destruction of the solid-electrolyte interphase (SEI) during charging and discharging, which reduces lifespan and capacity.
Innovation Solution
A coffee ground composition is used to create a high-capacity silicon anode active material by inserting nano-silicon into the pores of coffee grounds, which are then carbonized, thereby suppressing volume expansion and enhancing electrical conductivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon is used as anode active material to achieve high capacity, then capacity is improved, but volume expansion and contraction occur causing unstable SEI and low lifespan
Solution Approach 1:
Silicon particles are inserted into the inner space of carbon nanotubes, creating a nested structure where silicon is contained within CNTs. This nesting approach allows silicon to expand and contract within the confined space of CNTs, preventing damage to the overall structure and maintaining stable SEI formation, thus improving lifespan while preserving high capacity
Solution Approach 2:
A composite structure is formed by combining carbon nanotubes with silicon particles. The carbon nanotube matrix provides structural stability and electrical conductivity, while silicon particles provide high capacity. This composite approach allows the material to benefit from both components, achieving high capacity with improved structural stability and lifespan
2Quantity of substance
If silicon material is used to achieve high capacity, then capacity is improved, but lithium ion diffusion rate is slow due to low electrical conductivity
Solution Approach 1:
The composite of carbon nanotubes and silicon particles creates a conductive network that enhances electrical conductivity. Carbon nanotubes have inherently high electrical conductivity, which compensates for silicon's low conductivity, thereby improving lithium ion diffusion rate while maintaining high capacity
3Speed
If carbon nanotubes are used to improve rate capability characteristics, then electrical conductivity and surface area are improved, but device complexity increases
Solution Approach 1:
The nested structure of silicon particles within carbon nanotubes provides a straightforward geometric arrangement that simplifies the overall device architecture. The CNTs naturally form a network that encapsulates silicon particles, eliminating the need for additional structural components or complex assembly processes, thus improving rate capability without significantly increasing device complexity
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 approach improves the charging and discharging characteristics, including initial efficiency, capacity, and lifespan of the battery, while also providing an environmentally friendly and cost-effective solution by recycling coffee grounds.
Implementation Method 1
a high-capacity silicon anode active material by inserting nano-silicon into the pores of coffee grounds, which are then carbonized
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure is to provide a coffee ground composition which can suppress the phenomenon of silicon crushing and peeling due to volume expansion during charging and discharging, and has improved charging and discharging characteristics such as initial efficiency, capacity, and lifespan characteristics, and a secondary battery anode material comprising the same. The present disclosure can contribute to the protection of the natural environment through the preparation of a lithium secondary battery high-capacity silicon anode active material prepared using coffee grounds, an environmental pollutant, and can lower a lithium secondary battery anode material preparation cost with the high-capacity silicon anode active material using the coffee grounds. In addition, the present disclosure not only can suppress the phenomenon of silicon crushing and peeling due to volume expansion during charging and discharging, but also can improve charging and discharging characteristics such as initial efficiency, capacity, and lifespan characteristics.