Development of a Lightweight LTO/Cu Electrode as a Flexible AnodeviaEtching Process for Lithium-Ion Batteries

Abstract

In recent years, flexible energy storage devices have attracted the growing demand for flexible electronic systems. Therefore, research on reliable electrodes with high mechanical flexibility and good electronic and lithium-ion conductivity has become critical. Carbon-coated Li 4 Ti 5 O 12 (LTO) nanostructures find essential applications in high-performance lithium-ion batteries (LiBs). Nevertheless, the conventional copper current collector with a thickness of several micrometers accounts for a large proportion of the LiB, making the low-energy density LiB with much less flexibility. Here, hundred nm-thick (LTO/Cu) copper foil–LTO nanostructures are fabricated using a scalable and straightforward process which can be assembled into a film into a flexible, lightweight electrode by etching a conventional copper foil to form an ultra-thin copper layer for LIBs (<1 μm). This process provides essential flexibility to the as-prepared electrode and provides template support for simple fabrication. The LiB cell using the novel LTO/Cu as the anode exhibits an energy capacity of 123 mA h/g during 40 charge–discharge cycles at a 0.1C rate. Besides, the coulombic efficiency of the LiB using LTO/Cu remains over 99% after 40 cycles. These results show the uses of this novel anode and its potential in high-density and flexible commercial lithium-ion batteries.

Intertwined CNT Assemblies as an All-Around Current Collector for Volume-Efficient Lithium-Ion Hybrid Capacitors

“…Innovative current collector materials are required for the development of practical clean energy (renewable and hydrogen energies) power conversion systems as well as the advancement in system-powered wearable devices and electric vehicles. − New current collectors should meet the following requirements: (i) large specific surface area to allow high mass loading of active materials and low interfacial contact resistance, (ii) low density to enhance the weight fractions of the active materials relative to the total mass of electrodes, (iii) efficient heat dissipation during charge and discharge cycling, (iv) a wide range of potential windows for maintaining electrochemical stability, and (v) good mechanical robustness for the mass production of commercial cells, which includes coating, rolling, and winding processes . A number of alternatives based on two- or three-dimensional metal current collectors in the forms of meshes, foams, , and ultrathin films have been suggested. Nevertheless, metal-based current collectors are insufficient to meet this need due to the intrinsically low yield strains and heavy weight of metals.…”