Heterolayered, One-Dimensional Nanobuilding Block Mat Batteries

• Published in: Nano letters Vol. 14; no. 10; pp. 5677 - 5686
• Main Authors: Choi, Keun-Ho, Cho, Sung-Ju, Chun, Sang-Jin, Yoo, Jong Tae, Lee, Chang Kee, Kim, Woong, Wu, Qinglin, Park, Sang-Bum, Choi, Don-Ha, Lee, Sun-Young, Lee, Sang-Young
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 08-10-2014
• Subjects: Anodes; Blocking; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electric batteries; Electrodes; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials science; Methods of nanofabrication; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanotubes; Physics; Separators; Single wall carbon nanotubes; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Nanomat batteries; cellulose nanofibrils; heterolayer; one-dimensional nanobuilding block; separator/electrode assembly; single-walled carbon nanotubes; Electronic conductivity; Stacking sequence; Cellulose; Electrode material; Nanostructures; Carbon; Flexibility; Interfaces; Singlewalled nanotube; Electrochemical properties; Electrolytes; Active material; Nanomaterial synthesis; Nanoporosity; Crystal structure
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl5024029

The rapidly approaching smart/wearable energy era necessitates advanced rechargeable power sources with reliable electrochemical properties and versatile form factors. Here, as a unique and promising energy storage system to address this issue, we demonstrate a new class of heterolayered, one-dimensional (1D) nanobuilding block mat (h-nanomat) battery based on unitized separator/electrode assembly (SEA) architecture. The unitized SEAs consist of wood cellulose nanofibril (CNF) separator membranes and metallic current collector-/polymeric binder-free electrodes comprising solely single-walled carbon nanotube (SWNT)-netted electrode active materials (LiFePO4 (cathode) and Li4Ti5O12 (anode) powders are chosen as model systems to explore the proof of concept for h-nanomat batteries). The nanoporous CNF separator plays a critical role in securing the tightly interlocked electrode–separator interface. The SWNTs in the SEAs exhibit multifunctional roles as electron conductive additives, binders, current collectors and also non-Faradaic active materials. This structural/physicochemical uniqueness of the SEAs allows significant improvements in the mass loading of electrode active materials, electron transport pathways, electrolyte accessibility and misalignment-proof of separator/electrode interface. As a result, the h-nanomat batteries, which are easily fabricated by stacking anode SEA and cathode SEA, provide unprecedented advances in the electrochemical performance, shape flexibility and safety tolerance far beyond those achievable with conventional battery technologies. We anticipate that the h-nanomat batteries will open 1D nanobuilding block-driven new architectural design/opportunity for development of next-generation energy storage systems.