Fabrication of Binder-Free Pencil-Trace Electrode for Lithium-Ion Battery: Simplicity and High Performance

Abstract

A binder-free and solvent-free pencil-trace electrode with intercalated clay particles (mainly SiO2) is prepared via a simple pencil-drawing process on grinded Cu substrate with rough surface and evaluated as an anode material for lithium-ion battery. The pencil-trace electrode exhibits a high reversible capacity of 672 mA h g–1 at 100 mA g–1 after 100 cycles, which can be attributed to the unique multilayered graphene particles with lateral size of few micrometers and the formation of Li x Si alloys generated by interaction between Li+ and an active Si produced in the electrochemical reduction of nano-SiO2 in the clay particles between the multilayered graphene particles. The multilayered graphene obtained by this process consists of 1 up to 20 and occasionally up to 50 sheets and thus can not only help accommodating the volume change and alleviating the structural strain during Li ion insertion and extraction but also allow rapid access of Li ions during charge–discharge cycling. Drawing with a pencil on grinded Cu substrate is not only very simple but also cost-effective and highly scalable, easily establishing graphitic circuitry through a solvent-free and binder-free approach.

Synthesis of Copper Oxide/Graphite Composite for High‐Performance Rechargeable Battery Anode

“…The positive G-band shift (about1 5cm À1 )i ndicates the presence of covalent bonding between the graphite surface and Cu oxide nanoparticles (CuÀ C). [24] In addition, according to previousr eports, the expansion of graphite can be confirmed by monitoring the negative shift in the peak position. The intensity ratios of graphite, GCuO 1:4, and GCuO 1:16 were0 .13, 0.66, and 0.74, respectively.I ncreases in the I D /I G ratio are generally the result of increased exposureo ft he edge planesa nd mis-alignedA Bs tacking in graphite.…”

“…In the anodic scan, the broader oxidation potential( % 2.5 V) came from the formation of CuO (Cu 0 + Li 2 OÐCuO + 2Li + ). [24] The cathodic and anodic peaks of the GCuO cell were similar to typical Cu oxide and graphite peaks. [24] The cathodic and anodic peaks of the GCuO cell were similar to typical Cu oxide and graphite peaks.…”

“…[35] In the graphite CV,t he anodic andc athodic peaks were observed at 0.30 (intercalation) and 0.02 V( deintercalation) versus Li/Li + . [24] These structural features accounted for the differences between the specific capacities, rate capabilities, and voltagep rofiles of the GCuO and graphite anodes. Specifically,t he cathodic peaks at 0.85, 1.3, and 2.17 V were attributed to Cu oxide reduction,a nd the peak at 0.26 V was attributed to graphite intercalation.T he anode peaks at 0.016 and 2.5 Vr esulted fromg raphite de-intercalationa nd Cu oxidation, respectively.I nterestingly,t he intercalation and deintercalation current densities were increased upon the addition of the Cu ion complex.…”

“…[16,17] Recently,m etal (Sn, Si, Ge, etc. [24,25] Modified graphite has exhibiteds table storage capacities during charge/discharge processes. and carbonaceous (graphene, carbon nanotubes (CNTs)) materials have been proposed as next-generation anode materials because of their hight heoretical capacities.…”

“…[21][22][23] The modification of commercialized graphiteh as been proposed recently as an effective method for increasing cycling stability,a saresult of the expansion of the graphite interlayer distance. [24,25] Modified graphite has exhibiteds table storage capacities during charge/discharge processes. However,t he production of these anode materials involves complex, time-consuming, and hazardous processes such as stronga cid etching.…”