High volumetric capacity nanoparticle electrodes enabled by nanofluidic fillers

Abstract

Nanosized materials are widely applied in lithium-ion battery to improving power/energy performances. However, the low packing density of nanoparticles limits the volumetric capacity of electrodes. Calendering nanoparticle electrodes leads to pore destruction, electrolyte blocking and poor ion transport. This work reports unimpeded ion transport in ultracompact nanoparticle electrodes by nanofluidic additives that provide rapid ion pathways without loss of electrode density. Sub-micron commercial LiFePO4 particles, as a model cathode material, are deployed to fabricate the nanofluidic-enhanced dense electrodes that show excellent volumetric capacities in liquid and gel polymer electrolytes, which surpass state-of-the-art LiFePO4 electrodes. This extraordinary performance (303.6 mAh cm−3 and 1026.2 Wh L–1 at 0.06 C) correlates with the conductive nanofluidic network through which lithium ions can move around swiftly. This nanofluidic strategy can be extended to other electroactive nanoparticles in the design of high-capacity compact batteries.