Multilayer Silicon Anode Structure for Stable Fast-Charging Batteries

The negative electrode is divided into multiple layers with different compositions. The first and third layers contain crystalline carbon with low silicon content, while the second layer contains silicon-containing particles with higher concentration. This segmentation allows different regions to perform different functions: the silicon-rich second layer provides high capacity, while the carbon-rich first and third layers stabilize volume changes and maintain ion delivery pathways.

Different regions of the negative electrode are given different local properties. The central second layer has high silicon content for maximum capacity, while the outer first and third layers have crystalline carbon dominance for structural stability and ion transport. This local quality differentiation resolves the contradiction by allowing high capacity in the center while maintaining charge-discharge rates at the boundaries.

The negative electrode active material layer is segmented into three distinct layers with varying silicon content. The second layer contains silicon-containing particles for high energy density, while the first and third layers contain crystalline carbon that remains stable during charge-discharge cycles, maintaining consistent ion delivery pathways despite volume changes in the silicon layer.

The crystalline carbon in the first and third layers acts as an intermediary that buffers the volume changes of silicon-containing particles in the second layer. This intermediary structure absorbs and distributes the mechanical stress from silicon expansion and contraction, preventing disruption of ion delivery pathways while allowing the silicon to contribute to high energy density.

The negative electrode is segmented into three layers with progressively varying compositions. The second layer has higher silicon and conductive binder concentration for enhanced charge-discharge rates, while the first and third layers have lower concentrations. This segmentation achieves improved productivity through optimized ion and electron transport pathways while keeping the structural complexity manageable through a regular repeating pattern.

The concentration of silicon-containing particles and conductive binder is systematically changed across the three layers. The second layer has higher concentrations of both silicon and conductive binder to enhance charge-discharge rates, while the first and third layers have lower concentrations. This parameter variation optimizes performance without requiring overly complex structures, as the changes follow a simple gradient pattern.