Paper TF+SE-TuM1
Investigations on LiMn_xNi_yO Thin Films Deposited by RF Sputtering using Powder Target for Thin Film Battery Applications

Tuesday, November 11, 2014, 8:00 am, Room 305

Cathode materials in the form of thin films for all solid state Li ion batteries (thin film batteries) application have attracted wide attention among the scientific community because of the inherent benefit of studying pure phase of the active materials without any binders and conductive additives such as carbon black, NMP etc [1,2]. In the present work thin films of LiMn_xNi_yO have been prepared in a cost effective approach using powder sputtering on nickel coated stainless steel (SS 304) substrates. Powder sputtering is more convenient with the advantages like less material consumption, slightly higher deposition rates and cost effective approach compared to pellet sputtering. The advantage of utilizing powder sputtering for the deposition and electrochemical performance of Li_xMnO_y thin films has been reported [3]. Post deposition annealing at 500 °C for one hour was carried out in air ambiance. XRD, XPS and electrochemical characterizations have been carried out to investigate the phase, surface atomic concentration and electrochemical performance. XPS analysis indicates the presence of manganese, nickel, oxygen, and lithium at the surface as shown in Figure. 1. Electrochemical investigations delivered a specific discharge capacity of 54 µAH. µm^-1.cm^-2 in the potential window 2.0-4.4 V vs Li/Li⁺ in the first discharge cycle. Charge discharge profile up to 40 cycles have shown in the Figure.2. Discharge capacity values are in good agreement with the literature achieved using pellet sputtering.

References:

1. J.M. Tarascon, M. Armand. Nature 414, 359 (2001)

2. J.B. Bates, N.J. Dudney, B. Neudecker, A. Ueda, C.D. Evans. Solid State Ionics 135, 33– 45 (2000)

3. K.Yellareswara Rao, D. Shanmugha sundaram, C.S. Nimisha, Tirupathi Rao Penki, N. Munichandraiah, G. Mohan Rao. J. Electrochem. Soc 161, A28-A32 (2014)