Using Orthogonal Ploughing/Extrusion to Fabricate Three-Dimensional On-Chip-Structured Current Collector for Lithium-Ion Batteries

Abstract

The surface microstructure of the current collectors significantly affects the electrochemical performance of lithium-ion batteries (LIBs). This study shows that an effective method of orthogonal ploughing/extrusion is to fabricate three-dimensional (3D) microstructures directly on a copper plate used as the current collector for LIBs. Such an on-chip-structured current collector avoids introducing additional layers or components, dispenses with complex fabrication and integration, as well as provides abundant surface structures and morphologies. It is simply combined with mesocarbon microbeads graphite powders to form the anode electrode of CR2032 coin half-cells. Results indicate that the prepared current collector facilitates a high reversible discharge specific capacity of 341.8 mAh g–1 after 200 cycles at a current rate of 0.2 C with a capacity retention rate as high as 98.6%. This performance is significantly higher than the traditional bare copper current collector which maintains only 262.2 mAh g–1 with a capacity retention rate of 79.6% at 0.2 C after 100 cycles. It is proven that the combined microstructures of grooves, burrs, and reentrant cavities formed on the surface of the 3D on-chip-structured current collector effectively improve the electrochemical performance of LIBs in terms of reversible specific capacity, cycling stability, electrical conductivity, and Coulombic efficiency.

Regulating Lithium Electrodeposition with Laser-Structured Current Collectors for Stable Lithium Metal Batteries

“…In extreme cases, lithium dendrites form, penetrate the separator, and result in an internal short. , The dendrite issue raised significant safety concerns which led to the recall of a large number of LMBs in Japan in 1990 due to serious failures. Apart from that, repeated deposition and stripping on the current collector easily cause the volume changes of materials, leading to the rupture of SEI. , The change of the material structure finally deteriorates the cyclic performance and destabilizes the battery.…”

“…Apart from that, repeated deposition and stripping on the current collector easily cause the volume changes of materials, leading to the rupture of SEI. 18,19 The change of the material structure finally deteriorates the cyclic performance and destabilizes the battery.…”

Lightweight Through-Hole Copper Foil as a Current Collector for Lithium-Ion Batteries

“…However, the commercial Cu foil with a smooth surface has poor adhesion to active materials. As a result, the anode active material tends to shed from the Cu current collector during a long period of services, causing an increase in internal resistance and a decrease in cyclic performance . Therefore, rational structure design of Cu foil is an effective way to reduce its weight and to improve the adhesion to the active materials so as to enhance the specific capacity and cyclic performance of LIBs. , …”

“…As a result, the anode active material tends to shed from the Cu current collector during a long period of services, causing an increase in internal resistance and a decrease in cyclic performance. 14 Therefore, rational structure design of Cu foil is an effective way to reduce its weight and to improve the adhesion to the active materials so as to enhance the specific capacity and cyclic performance of LIBs. 15,16 A variety of methods have been reported to fabricate current collectors with modified surface structures.…”

Highly Reduced Graphene Assembly Film as Current Collector for Lithium Ion Batteries

“…Moreover, the adhesion ability of a metal current collector to the electrode material is usually weak, leading to a volume expansion effect during the charge and discharge processes and decreasing performance at a high rate . To solve such problems, structures of metal current collectors with roughened surfaces, such as nanoporous, nanoneedles, and nanonetworks, have been designed. − However, the high-quality density of the metal itself still limits the increase in the energy density of the battery. More importantly, metal foil is susceptible to local corrosion during long-term cycles, which reduces the service life of the battery.…”