Multi-Interface Strategy for Electrode Tailoring Toward Fast-Charging Lithium-Ion Batteries

초록

Thick and dense graphite anodes used in lithium-ion batteries (LIBs) suffer from sluggish reaction kinetics at the electrode level, causing Li metal plating on their surfaces and significant capacity decay at high charging currents. Thus, it is crucial to tailor electrodes based on a comprehensive understanding of the complex reaction kinetics to realize fast-charging LIBs. A multi-interface strategy is proposed for electrode tailoring using Al2O3 nanoparticles to enhance fast-charging capability while suppressing Li metal plating. Molecular dynamics simulations suggest that the incorporated Al2O3 nanoparticles perturb the charge and molecule distributions in the boundary layer, forming an “interfacial highway” for facile Li+ transport at the Al2O3/electrolyte interface. This pushes Li+ deeper into the electrode and homogenizes the Li+ flux across the electrode’s top surface. A full cell assembled with the Al2O3-decorated graphite electrode (areal capacity of 4.4 mAh cm−2) exhibits excellent cyclability with a capacity retention of 83.4% over 500 cycles even at a 2C rate without any noticeable signal for undesirable Li plating. The role of interfacial highways predicted by theoretical computations is further validated using a pouch-type full cell (500 mAh). These findings provide insights into the interfacial and microstructural design of high-capacity graphite electrodes for fast-charging, long-cycling LIBs.

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