3D Nanoporous Nanowire Current Collectors for Thin Film Microbatteries

• Published in: Nano letters 2012-03, Vol.12 (3), p.1198-1202
• Main Authors: Gowda, Sanketh R, Leela Mohana Reddy, Arava, Zhan, Xiaobo, Jafry, Huma R, Ajayan, Pulickel M
• Format: Article
• Language: English
• Subjects: Accumulators; Aniline Compounds - chemistry; Collectors; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition; Design engineering; Electric Power Supplies; Electrodes; Energy Transfer; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Membranes, Artificial; Microelectrodes; Miniaturization; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanostructures - chemistry; Nanostructures - ultrastructure; Nanotubes; Nanowires; Particle Size; Physics; Porosity; Quantum wires; Roughness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin films; Three dimensional
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl2034464

Conventional thin film batteries are fabricated based on planar current collector designs where the high contact resistance between the current collector and electrodes impedes overall battery performance. Hence, current collectors based on 3D architectures and nanoscale roughness has been proposed to dramatically increase the electrode-current collector surface contact areas and hence significantly reduce interfacial resistance. The nanorod-based current collector configuration is one of several 3D designs which has shown high potential for the development of high energy and high power microbatteries in this regard. Herein we fabricate a nanoporous nanorod based current collector, which provides increased surface area for electrode deposition arising from the porosity of each nanorods, yet keeping an ordered spacing between nanorods for the deposition of subsequent electrolyte and electrode layers. The new nanostructured 3D current collector is demonstrated with a polyaniline (PANI)-based electrode system and is shown to deliver improved rate capability characteristics compared to planar configurations. We have been able to achieve stable capacities of ∼32 μAh/cm2 up to 75 cycles of charge/discharge even at a current rate of ∼0.04 mA/cm2 and have observed good rate capability even at high current rates of ∼0.8 mA/cm2.