3D LiMn₂O₄ thin-film electrodes for high rate all solid-state lithium and Li-ion microbatteries

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.

Recent Developments of Nanomaterials and Nanostructures for High‐Rate Lithium Ion Batteries

“…[308] Recently, a novel synthesis route was developed by Labyedh et al, in which a stack of electrolytic manganese dioxide and Li 2 CO 3 was first deposited on either a planar surface or a substrate with a pillar array (aspect ratio > 20), and then a conformal and crack-free film of spinel LiMn 2 O 4 was deposited by a solid-state reaction (as shown in Figure 31 a). [309] A competitive capacity of 0.4 mAh cm À 3 (theoretical capacity: 1.27 mA g cm À 3 ) was achieved at an ultrahigh current rate 100 C (1 C = 17.8 μA cm À 2 ) for the 3D electrodes, which is due to the synergistic effects of the decreased diffusion length and the increased effective surface area. [309] The undesirable dissolution of manganese and molecule distortion during charge and discharge limit the application of lithium manganese oxides as a cathode material at high current densities (> 500 mA g À 1 ).…”

“…[309] A competitive capacity of 0.4 mAh cm À 3 (theoretical capacity: 1.27 mA g cm À 3 ) was achieved at an ultrahigh current rate 100 C (1 C = 17.8 μA cm À 2 ) for the 3D electrodes, which is due to the synergistic effects of the decreased diffusion length and the increased effective surface area. [309] The undesirable dissolution of manganese and molecule distortion during charge and discharge limit the application of lithium manganese oxides as a cathode material at high current densities (> 500 mA g À 1 ). [310] Substitution of manganese ions with other metal cations was investigated in order to improve the electrochemical stability and rate performance of LMO cathodes.…”

“…Exceptional specific capacities of devices prepared with cubic and spherical LiMn 2 O 4 nanomaterials at high current rates were reported (96.4 mAh g −1 and 88.3 mAh g −1 at 20 C, 1 C=148 mA g −1 ) . Recently, a novel synthesis route was developed by Labyedh et al., in which a stack of electrolytic manganese dioxide and Li 2 CO 3 was first deposited on either a planar surface or a substrate with a pillar array (aspect ratio >20), and then a conformal and crack‐free film of spinel LiMn 2 O 4 was deposited by a solid‐state reaction (as shown in Figure a) . A competitive capacity of 0.4 mAh cm −3 (theoretical capacity: 1.27 mA g cm −3 ) was achieved at an ultrahigh current rate 100 C (1 C=17.8 μA cm −2 ) for the 3D electrodes, which is due to the synergistic effects of the decreased diffusion length and the increased effective surface area …”

“…(a) SEM image of a planar Ni/LMO electrode after the solid-state reaction at 350°C (the inset is the SEM image illustrating a conformal layer of Ni/ LMO created on an array of pillars with an aspect ratio greater than 20). [309] Reproduced with permission from Ref. [309].…”

Tunnel Intergrowth LixMnO2 Nanosheet Arrays as 3D Cathode for High‐Performance All‐Solid‐State Thin Film Lithium Microbatteries

“…Although TFBs based on the commercialized cathode materials such as LiCoO 2 and LiMn 2 O 4 for lithium‐ion batteries (LIBs) exhibit promising electrochemical performance, the necessary high annealing/deposition temperatures (usually >500 °C) for such cathode films restrict their on‐chip integration and potential applications in microelectronics. [ 3–6 ] A high temperature processing is not endurable for the integrated circuits for complementary metal oxide semiconductor (CMOS), and it greatly limits the choice of substrate materials. Especially for flexible electronics, most of the cheap and flexible plastic substrates cannot withstand a temperature higher than 200 °C for long time processing.…”