Relationship between Pore Design on Current Collectors, the Reaction Temperature and the Rate of Li⁺ Ion Pre-doping Reaction to Laminated Graphite/Porous Current Collector Anodes

Abstract

The fabrication process of porous copper (Cu) current collectors having the pore diameter (3–50 µm) and the rate of opening area (1–4%) was developed with a system constructed with a pico-second pulse laser and a polygon mirror. The fabricated porous Cu current collectors were used to evaluate the porous design on the Cu current collector for exhibiting higher Li⁺ doping reaction rate with cells in which graphite electrodes were laminated with separators and the laminated graphite anode opposites to Li metal through a separator. It was found in this study that the conditions of hole diameter (5 µm) and the rate of opening area (1%) is the best one to realize high Li⁺ doping rate and that the rate determining step of the pre-doping reaction is the diffusion of Li⁺ ion in the pore of the Cu porous current collectors.