To address the growing demand for fast-charging lithium-ion batteries in electric vehicles

large-scale energy storage systems

and portable electronic devices

and to overcome the sluggish ion transport kinetics

severe polarization

and limited cycle life exhibited by conventional electrodes under high-current operating conditions

this study investigates the design of a multiscale three-dimensional conductive network architecture and its optimization for enhanced ion transport.First

based on characteristic time constant theory

the kinetic relationship between electron conduction and ion diffusion during fast charging is quantitatively analyzed

demonstrating that ion transport becomes the dominant rate-limiting factor at charging rates above 10 C. Accordingly

a design strategy based on dual continuity and kinetic matching of electron and ion transport pathways is proposed. The mechanisms by which the three-dimensional conductive network reduces transport resistance and mitigates polarization by establishing efficient electron-conduction pathways and optimized ion-diffusion channels are systematically elucidated. An evaluation framework centered on the dimensionless structural efficiency factor (

β

=

ε

/

τ

) is established

and a hierarchical collaborative design strategy spanning the micro-

meso-

and macro-scales is developed to identify the optimal structural parameters at each scale. A multiscale

multiphysics numerical model is established using COMSOL Multiphysics 6.0 with clearly defined modeling assumptions and applicability rang

es (porosity 30%—55%; graphene content 2%—5%; charging rate: ≤12 C). Multi-objective optimization using response surface methodology enables precise matching between structural parameters and transport performance. The electrodes are fabricated using an integrated process combining three-dimensional printing

in situ

sintering

and dispersion techniques

achieving a production rate of 50 electrodes per hour and a material utilization efficiency exceeding 95%

thereby demonstrating strong potential for scalable manufacturing. Electrochemical characterization shows that the optimized electrode delivers a specific capacity of 138 mAh/g at a high charging rate of 10 C

with a coulombic efficiency of 94.5% and a capacity retention of 91.3% after 1000 charge-discharge cycles. The optimized architecture increases the lithium-ion diffusion coefficient to 1.2×10

-11

cm

2

/s and reduces the charge-transfer resistance to 75 Ω·cm

2

. Additionally

the electrode maintains excellent electrochemical performance over a wide operating temperature range

from -20℃ to 55℃. Finally

the broader applicability of the proposed multiscale design strategy is discussed for silicon anodes

sulfur cathodes

and composite solid-state electrolyte electrodes. Remaining challenges

including the long-term stability of ZrO

2

coating layers and interfacial fatigue mechanisms

are also identified. These findings provide valuable theoretical guidance and practical support for the industrial development of high-rate

fast-charging lithium-ion batteries.