Binder free porous ultrafine/nano structured LiCoO2 cathode from plasma deposited cobalt

Abstract Increasing global demand for rechargeable lithium (Li) ion batteries has been driving the research on innovative processing techniques and material systems for cheaper production of battery electrodes. While cost reduction is important, obtaining desired microstructures in the active electrode material is also very critical for efficient performance of the batteries. Conventional processing of bulk scale Li-ion battery electrodes involves time consuming and multi-step processes starting from the production of active powder materials, blending with conductive additives and binders to develop the electrode material coating on a current collector. On the other hand, thin film battery technologies employ expensive vapor based or sputtering or laser ablation techniques to develop the electrodes. In this study, an innovative, rapid and a two step scalable manufacturing process has been developed. While capable of developing porous and ultrafine/nano structured oxide based LiCoO 2 cathode material directly on a charge collector from metallic Cobalt (Co) coatings, the process does not require polymeric binders. Following this approach, LiCoO 2 cathodes were synthesized directly on a stainless steel charge collector from plasma sprayed Co coatings via thermal treatments using aqueous LiNO 3 solution. X-ray diffraction (XRD) studies confirmed presence of LiCoO 2 hexagonal phase. Microstructural and phase analysis showed porous active material with ultrafine/nano structural features along with imperfections (e.g., dislocations). Electrochemical characterization illustrated an average voltage around 3.9 V with a specific discharge capacity around 70–85% of the nominal capacity (∼138 mAh/g) against Li counter electrode. However, process optimization in terms of plasma spray coatings and thermal treatments, and addition of carbon may enhance the performance of LiCoO 2 electrodes. Absence of polymeric binders makes these electrodes suitable for high temperature battery applications.

[1]  Ermete Antolini,et al.  Synthesis and Thermal Stability of LiCoO2 , 1995 .

[2]  S. Moon,et al.  Thermal analysis of LixCoO2 cathode material of lithium ion battery , 2009 .

[3]  Ermete Antolini,et al.  LiCoO2: formation, structure, lithium and oxygen nonstoichiometry, electrochemical behaviour and transport properties , 2004 .

[4]  Lisa C. Klein,et al.  Synthesis of electrochemically active LiCoO2 and LiNiO2 at 100 °C , 1996 .

[5]  G. Bruni,et al.  Solid state synthesis of stoichiometric LiCoO2 from mechanically activated Co–Li2CO3 mixtures , 2006 .

[6]  Lisa C. Klein,et al.  Cobalt dissolution in LiCoO2-based non-aqueous rechargeable batteries , 1996 .

[7]  J. Dahn,et al.  Structure and electrochemistry of LiMO2 (M=Ti, Mn, Fe, Co, Ni) prepared by mechanochemical synthesis , 1998 .

[8]  B. Fultz,et al.  Mechanism of electrochemical performance decay in LiCoO2 aged at high voltage , 2004 .

[9]  M. Armand,et al.  Issues and challenges facing rechargeable lithium batteries , 2001, Nature.

[10]  Michael M. Thackeray,et al.  Structure and electrochemistry of lithium cobalt oxide synthesised at 400°C , 1992 .

[11]  M. Carewska,et al.  Formation of Li- and Mg-Doped LiCoO2 Powders: a BET Analysis , 1999 .

[12]  B. Dunn,et al.  On the correlation between mechanical flexibility, nanoscale structure, and charge storage in periodic mesoporous CeO(2) thin films. , 2010, ACS nano.

[13]  I. Uchida,et al.  Electrochemical characterization of thin-film LiCoO2 electrodes in propylene carbonate solutions , 1997 .

[14]  B. Huang,et al.  Electrochemical evaluation of LiCoO2 synthesized by decomposition and intercalation of hydroxides for lithium-ion battery applications , 1998 .

[15]  Lech Pawlowski,et al.  The Science and Engineering of Thermal Spray Coatings , 1995 .

[16]  Yan‐Bing He,et al.  The thermal stability of fully charged and discharged LiCoO2 cathode and graphite anode in nitrogen and air atmospheres , 2008 .

[17]  Jin-Song Hu,et al.  Nanostructured Materials for Electrochemical Energy Conversion and Storage Devices , 2008 .

[18]  A. K. Shukla,et al.  Novel solution-combustion synthesis of LiCoO2 and its characterization as cathode material for lithium-ion cells , 2001 .

[19]  M. Whittingham,et al.  Lithium batteries and cathode materials. , 2004, Chemical reviews.

[20]  M. Yoshimura,et al.  Fabrication in a Single Synthetic Step of Electrochemically Active LiMO2 (M = Ni and Co) Thin-Film Electrodes Using Soft Solution Processing at 20−200 °C , 1998 .

[21]  Chang Liu,et al.  Advanced Materials for Energy Storage , 2010, Advanced materials.

[22]  G. Pistoia,et al.  Lithium batteries : science and technology , 2003 .

[23]  J. Pereira‐Ramos,et al.  Low-temperature cobalt oxide as rechargeable cathodic material for lithium batteries , 1995 .

[24]  Laurence Croguennec,et al.  On the metastable O2-type LiCoO2 , 2001 .

[25]  Michael M. Thackeray,et al.  Spinel versus layered structures for lithium cobalt oxide synthesised at 400°C , 1993 .

[26]  John B. Goodenough,et al.  LixCoO2 (0, 1980 .

[27]  Sanjay Sampath,et al.  Thermal Spray: Current Status and Future Trends , 2000 .

[28]  Y. Baba,et al.  Thermal stability of LixCoO2 cathode for lithium ion battery , 2002 .