Laser micro-structuring of magnetron-sputtered SnOx thin films as anode material for lithium ion batteries

Abstract

SnO x electrode thin films for lithium ion batteries were deposited by reactive and non-reactive rf magnetron sputtering of a SnO 2 target in an argon-oxygen atmosphere. Amorphous and nano-crystalline SnO x films could be synthesized, with regard to the O 2 :Ar volume ratio in the sputter gas which was adjusted to 0, 3.5 or 10%. Laser micro-structuring using a KrF excimer laser operating at a wavelength of k = 248 nm was applied to create free-standing microstructures. Thus, the active surface of the anode material was significantly increased. Furthermore, it was expected that the large volume changes during electrochemical cycling of SnO x could be better compensated by a microstructured surface. The laser parameters were optimized in a way which leads to structures without any defects and little debris. Depending on the laser fluence and pulse number, free-standing conical structures could be formed with a horizontal spacing of \0.5 lm up to 2 lm. The structured and unstructured thin films were cycled in a battery tester against metallic lithium. The structured SnO x thin films exhibited significantly better battery performance with respect to cycling stability.

A polymerized C60 coating enhancing interfacial stability at three-dimensional LiCoO2 in high-potential regime

“…All laser structuring experiments were carried out under ambient air without using any exhaust to allow the formation of self-organizing microstructures on the cathode material. The loss of active material by this type of laser structuring is limited to 0e10 wt% [5,9,10,26]. Laser-annealing of unstructured and laser structured thin films was performed in order to form HT-LCO using a high power diode laser (FLS IronScan, Fisba Optik AG) with a maximum laser power of 50 W operating at a wavelength of 940 nm.…”

Fs-laser microstructuring of laser-printed LiMn2O4electrodes for manufacturing of 3D microbatteries

“…A summary of 3D battery architectures is given in [12]. For this reason, excimer laser structuring of thin and thick film electrode materials was investigated in the past for increasing the active surface area by forming 3D microstructures directly into the active material [13][14][15][16][17]. Furthermore, conical microstructures could be formed in compact thin films as well as porous thick films [18].…”

Femtosecond laser patterning of lithium-ion battery separator materials: impact on liquid electrolyte wetting and cell performance

“…A powerful technique to enhance the wetting properties of electrodes is laser patterning. Laser patterning processes have been developed for thin film electrode materials [4][5][6][7][8][9][10] as well as for thick tape-casted standard materials [11][12][13][14][15][16]. For the latter it could be shown that laser patterning of electrodes into three-dimensional (3D) micro-structures turns regular electrode surfaces into super-wicking accompanied with drastically increased electrolyte wetting speed [14][15][16].…”