LSO-Graphite Anode Composition for Fast-Charging Li-Ion Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion batteries face challenges in achieving high energy and power density, especially for rapid charging applications in hybrid and electric vehicles, where traditional negative electrodes like graphite fall short in providing both high energy storage and fast charging capabilities.
Innovation Solution
The development of a negative electrode comprising a lithiated silicon oxide (LSO) and carbonaceous material, such as graphite, with a specific weight percentage distribution, along with electrically conductive particles and a polymeric binder, enhances the energy density and cyclability of lithium-ion batteries, allowing for fast charging and reduced compressive pressure during assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional graphite negative electrodes are used, then the battery structure is simple and manufacturing is easy, but the energy density and fast charging capability are insufficient
Solution Approach 1:
The negative electrode uses a composite material system consisting of lithiated silicon oxide (LSO) particles, carbonaceous material (such as graphite), electrically conductive particles, and polymeric binder. This composite structure combines the high capacity of LSO with the stability and conductivity of carbonaceous materials, achieving energy density greater than 290 Wh/kg while maintaining structural integrity and fast charging capability
Solution Approach 2:
The patent optimizes the weight percentage distribution of components in the negative electrode: LSO at 10-30 wt%, carbonaceous material at 70-90 wt%, and controlled amounts of conductive particles and binder. This parameter optimization balances energy density, conductivity, and mechanical stability, resolving the contradiction between high energy density and manufacturing simplicity
2Quantity of substance
If high energy density materials are used to increase energy storage, then the energy capacity improves, but the charging speed decreases
Solution Approach 1:
The negative electrode structure creates different local environments: LSO particles provide high capacity regions, while carbonaceous material provides high conductivity regions, and conductive particles create conductive networks. This local quality differentiation allows simultaneous achievement of high energy capacity and fast charging speed by optimizing the spatial distribution and interaction of different materials
3Quantity of substance
If lithiated silicon oxide is used to achieve high energy density, then the energy storage capacity increases, but the electrode swelling increases during cycling
Solution Approach 1:
Carbonaceous material acts as an intermediary between LSO particles, providing a stable matrix that accommodates LSO volume changes during lithium insertion/extraction. The carbon material absorbs mechanical stress and prevents direct contact between LSO particles, reducing swelling while maintaining electrical conductivity through the carbon network
Solution Approach 2:
The carbonaceous material and binder are pre-configured to form a cushioning matrix around LSO particles before cycling begins. This pre-established support structure anticipates and accommodates the swelling that occurs during lithium insertion, preventing structural degradation and maintaining electrode integrity throughout the battery lifecycle
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
This configuration results in lithium-ion batteries with improved energy density, enhanced capacity retention, and fast charging capabilities, achieving an energy density of greater than 290 Wh/kg and maintaining stability through 500 charge-discharge cycles with minimal swelling.
Implementation Method 1
positive electrode materials for lithium batteries typically comprise an electroactive material which can be intercalated or reacted with lithium ions
Implementation Method 2
lithiated silicon oxide (LSO) negative electroactive material
Implementation Method 3
Lithium ions move from a cathode (positive electrode) to an anode (negative electrode) during charging of the battery, and in the opposite direction when discharging the battery
Implementation Method 4
electrically conductive particles and a polymeric binder, enhances the energy density and cyclability of lithium-ion batteries
Data Source
AI summary
A negative electrode for an electrochemical cell that cycles lithium includes a negative electrode including an electroactive material layer disposed on a current collector that has lithiated silicon oxide (LSO) negative electroactive material at ≥ about 10 weight % to ≤ about 30 weight % of a total weight of the electroactive material layer and a carbonaceous negative electroactive material, such as graphite. An electrochemical cell that incorporates such a negative electrode may also include a second electrode comprising a porous positive active material layer comprising a positive lithium containing, nickel-rich electroactive material, such as a lithium nickel manganese cobalt aluminum oxide, a porous separating layer disposed between the first electrode and the second electrode and an electrolyte disposed in pores of the separating layer.