Graphite Negative Plate Density Tuning for Low-Temperature Wettability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current battery technologies face a trade-off between high compacted density for increased energy density and low-temperature wettability, leading to decreased cycle life and low-temperature liquid absorption capacity.
Innovation Solution
A negative plate design with a specific particle size distribution, crystal size, and compacted density, optimized through relationships involving DFW, Dv50, La, and PD, ensures both high compacted density and good low-temperature wettability, enhancing electrolyte absorption and cycle life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the compacted density of the plates is increased to improve energy density, then the energy density of the battery is improved, but the low-temperature liquid absorption capacity (wettability) of the plates decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution parameters (D10, D50, D90) of the graphite anode active material and establishing specific mathematical relationships between these parameters and compacted density. By adjusting the particle size distribution within defined ranges and maintaining specific ratio relationships (e.g., D90/D10 between 2.5-4.5), the patent achieves optimal balance between compacted density and low-temperature wettability, resolving the technical contradiction between energy density and low-temperature performance
Solution Approach 2:
The patent employs composite material principles by creating a multi-component anode active material system that includes graphite particles with specific size distributions and controlled crystal structures. The composite nature of the material system, with particles of different sizes and crystal orientations, enables simultaneous achievement of high compacted density and good electrolyte wettability at low temperatures, thus resolving the contradiction between energy density and low-temperature liquid absorption capacity
2Quantity of substance
If the compacted density of the plates is increased to improve energy density, then the energy density of the battery is improved, but the cycle life of the battery decreases
Solution Approach 1:
The patent applies parameter changes by establishing specific mathematical relationships between particle size distribution parameters and compacted density. By controlling D10, D50, and D90 within defined ranges and maintaining specific ratio relationships, the patent achieves optimal compacted density that improves energy density while preserving cycle life through controlled material structure and porosity
Solution Approach 2:
The patent applies inversion by reversing the conventional approach: instead of simply increasing compacted density to maximize energy density, the patent defines an optimal compacted density range and establishes inverse relationships between particle size parameters and compacted density. This inverted approach ensures that energy density improvement does not come at the cost of cycle life degradation
Data Source
AI summary
The present disclosure discloses a negative plate, a secondary battery and an electrical device, and falls within the technical field of batteries. The negative plate of the present disclosure includes a negative current collector and an anode active material layer provided on a surface of the negative current collector, the anode active material layer includes an anode active material, the anode active material includes graphite, and the negative plate satisfies the following relationship: a=ln(DFW)+10×ln(DV50) +1/3(La) +26.5, b=PD, a/45-b≥0.05. By reasonably controlling a particle diameter distribution of the anode active material in the negative plate, as well as a crystal size and a compacted density of the negative plate, the negative plate of the present disclosure maintains good wettability at a higher compacted density and has good liquid absorption capacity for an electrolyte solution, and a battery containing the negative plate has excellent cycle life.