SCHEDULED MAINTENANCE
3D LiMn2O4 thin-film electrodes for high rate all solid-state lithium and Li-ion microbatteries†
*ab
Felix
Mattelaer,
c
Abstract
In this paper, we report on the fabrication and characterization of functional 3D LiMn2O4 thin-film electrodes giving a footprint capacity of 0.5 mA h cm−2, i.e. surpassing any thin-film electrode reported thus far. Using a novel process based on a solid state reaction between electrolytic manganese dioxide (EMD) and Li2CO3 stacked-layers, crack-free, uniform and continuous lithium manganese oxide (LMO) thin films were fabricated on planar and high aspect ratio microstructured substrates. The fabricated LMO films are shown to have a stoichiometry close to that of spinel LiMn2O4 with a homogeneous elemental distribution throughout the layer. The prepared thin films are electrochemically active reaching a volumetric capacity of 1200 A h L−1, which is close to the theoretical capacity of spinel LiMn2O4. The few hundred nanometer thin-film morphology allows for use of both the 3 V and 4 V regions. The 3D LMO thin-film electrodes had 21 times the capacity of the planar LMO thin film with similar thickness due to the area enhancement and the excellent conformal coating of the high aspect ratio micropillar substrates. An excellent rate performance was demonstrated for both the planar and the high aspect ratio substrates where 48% and 30% of the theoretical LiMn2O4 capacity are maintained at very high C-rates of 20C and 100C, respectively.
Please wait while we load your content...
