Carbonaceous Anode Material for Capacity and First-Cycle Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current negative electrode active materials, such as graphite and hard carbon, have limited capacity, first Coulombic efficiency, and rate performance, which restricts the energy density, service life, and performance of secondary batteries.
Innovation Solution
A carbonaceous material with a specific CO2 adsorption ratio (A/B ≥ 1.7 cm3/(g×h) STP) is developed, which provides ample space for active ion storage and reversible intercalation, enhancing both capacity and first Coulombic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If graphite is used as negative electrode active material, then the battery structure is stable, but the theoretical gram capacity is only 372 mAh/g and energy density improvement is very limited
Solution Approach 1:
The patent uses biomass waste (rice husk) as a composite precursor containing both carbon and binder components, which after carbonization forms a composite carbonaceous material with improved capacity while maintaining structural stability. This composite approach allows simultaneous achievement of high capacity and structural integrity.
2Reliability
If graphite is used as negative electrode active material, then the battery structure is stable, but the interlayer spacing is small and rate performance improvement is limited
Solution Approach 1:
The patent changes the structural parameters of the carbonaceous material by controlling carbonization temperature (600-900°C) and using biomass precursors with different molecular structures, resulting in varied interlayer spacing (0.36-0.42 nm) that optimizes both structural stability and ion transport speed for improved rate performance.
3Speed
If hard carbon is used as negative electrode active material, then rapid intercalation and deintercalation of active ions is achieved, but capacity and first Coulombic efficiency are low
Solution Approach 1:
The patent creates local quality variations in the carbonaceous material by forming particles with heterogeneous internal structures including amorphous carbon regions, graphitic crystallites, and pore networks. This local structural diversity provides both fast ion transport pathways and high-capacity storage sites, resolving the contradiction between rate performance and capacity.
4Reliability
If additional conductive agents are added to improve battery performance, then conductivity is enhanced, but the preparation process becomes more complex and energy density is reduced
Solution Approach 1:
The biomass waste precursor serves multiple functions simultaneously: it provides carbon source, binder, conductive network, and structural framework. This multi-functionality eliminates the need for separate conductive agents and simplifies the preparation process while maintaining or improving conductivity and energy density.
5Reliability
If additional conductive agents are added to improve battery performance, then conductivity is enhanced, but energy density is reduced
Solution Approach 1:
The biomass-derived carbonaceous material provides conductivity through its inherent graphitic crystallites and carbon network structure, eliminating the need for additional conductive agents that would occupy volume and reduce energy density. The same material that provides structural framework also provides conductive pathways.
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 carbonaceous material achieves high energy density, long service life, and good rate performance for secondary batteries, while also simplifying the preparation method and reducing the need for additional conductive agents.
Implementation Method 1
In the CO2 adsorption test of the carbonaceous material, the total CO2 adsorption at 0° C. and a relative pressure P/P0 between 10−8 and 0.029 is recorded as A
Data Source
AI summary
A carbonaceous material where in the CO2 adsorption test of the carbonaceous material, the total CO2 adsorption at 0° C. and a relative pressure P/P0 between 10−8 and 0.029 is recorded as A, the adsorption time is recorded as B, and the carbonaceous material satisfies: A/B≥1.7 cm3/(g×h) STP, where STP is the standard condition, P represents the test pressure of CO2, and P0 represents the saturated vapor pressure of CO2 at 0° C.