Battery Electrolyte Kinetic Factor Tuning for Fast Cycling Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion batteries face challenges in achieving larger capacity, higher energy density, improved charging/discharging efficiency, and enhanced cycling stability, with current additives increasing production costs due to their unconventional nature.
Innovation Solution
An energy storage apparatus is designed with an electrolytic solution having a kinetic factor α controlled within the range of -10 ≤ α ≤ 30, influenced by viscosity, conductivity, diffusion coefficient, thermodynamic temperature, and molar concentration, ensuring efficient intercalation and deintercalation of electrolyte cations, thereby improving rate and cycling performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional additives are added to improve battery performance, then conductivity and cycling performance are improved, but production cost increases
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing a specific additive containing fluorinated cyclic carbonate and chain carbonate in a controlled weight ratio range (10:90 to 40:60). This compositional parameter change improves cycling performance while avoiding the use of expensive conventional additives, thus resolving the contradiction between reliability and manufacturing cost.
2Productivity
If charging/discharging rate is increased to improve efficiency, then power output increases, but lithium precipitation occurs and cycling stability deteriorates
Solution Approach 1:
The patent modifies the electrolyte composition parameters by adding fluorinated cyclic carbonate and chain carbonate in specific proportions, which changes the kinetic factor α to fall within -10 to 30. This parameter optimization enables efficient lithium ion transport at high rates while preventing lithium precipitation, thus improving both productivity and reliability simultaneously.
3Speed
If electrolyte viscosity is reduced to improve ion diffusion, then rate performance improves, but conductivity may be affected
Solution Approach 1:
The patent optimizes the electrolyte composition parameters by combining fluorinated cyclic carbonate with chain carbonate in specific weight ratios, which simultaneously optimizes both viscosity and conductivity parameters. The kinetic factor α control ensures that ion diffusion rate and conductivity are balanced, resolving the contradiction between speed and reliability.
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 apparatus achieves efficient charging and discharging without lithium precipitation, maintaining good rate and cycling performance across various temperatures, thus stabilizing the energy storage system.
Implementation Method 1
the electrolytic solution has a kinetic factor α satisfying the following formula: α = k1 × ε × InD + k2 × σ × T / 100C; wherein ε is viscosity of the electrolytic solution, D is diffusion coefficient of electrolyte cations in the electrolytic solution, σ is conductivity of the electrolytic solution
Implementation Method 2
D is diffusion coefficient of electrolyte cations in the electrolytic solution
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
The present invention relates to an energy storage apparatus, an energy storage system, and an electric device. The energy storage apparatus provided in the present application comprises an electrolytic solution, a positive electrode sheet, a separator, and a negative electrode sheet; the kinetic factor α of the electrolytic solution satisfies the formula: α = k1 × ε × InD + k2 × σ × T / 100C, and the kinetic factor α of the electrolytic solution satisfies: -10 ≤ α ≤ 30, wherein ε is the viscosity of the electrolytic solution, D is the diffusion coefficient of electrolyte cations in the electrolytic solution, σ is the electrical conductivity of the electrolytic solution, T is the thermodynamic temperature of the electrolytic solution, C is the molar concentration of an electrolyte, k1 is the viscosity correction coefficient of the electrolytic solution, and k2 is the electrical conductivity correction coefficient of the electrolytic solution; the positive electrode sheet is at least partially immersed in the electrolytic solution; the separator is arranged on one side of the positive electrode sheet and is at least partially immersed in the electrolytic solution; the negative electrode sheet is arranged on the side of the separator facing away from the positive electrode sheet, and is at least partially immersed in the electrolytic solution. The energy storage apparatus has good rate performance, cycle performance and low-temperature performance.