Ultra‐Lightweight 3D Carbon Current Collectors: Constructing All‐Carbon Electrodes for Stable and High Energy Density Dual‐Ion Batteries

• Published in: Advanced energy materials Vol. 8; no. 26
• Main Authors: Zhou, Zhili, Li, Na, Yang, Yazheng, Chen, Haosen, Jiao, Shuqiang, Song, Wei‐Li, Fang, Daining
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 14.09.2018
• Subjects: Accumulators; Aluminum; Anodes; Batteries; Carbon; carbon current collectors; Cathodes; Collectors; Copper; dual‐ion batteries; Electrochemical corrosion; Electrodes; Flux density; Foils; graphite cathodes; in situ optical observations; Ion diffusion; Life cycle engineering; Lightweight; mechanically and electrochemically stable; Weight reduction
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201801439

Dual‐ion batteries (DIBs) attract great interest because they allow two types of ions for reversibly intercalating into electrodes, resulting in various advantages. However, there are three critical problems using graphite‐based cathodes, namely, low active material proportion in the electrodes, current collector corrosion, and massive cathode variation. For addressing these problems, an ultra‐lightweight 3D carbon current collector (CCC) is developed to fabricate all‐carbon electrodes as both cathodes and anodes. Compared with the conventional DIBs using Al and Cu foils as current collectors, the DIBs with 3D CCC of electrically conductive pathways and sufficient ionic diffusion channels deliver enhanced specific capacity stabilized around 140 and 120 mAh g−1 at 0.5 and 1C, respectively. The electrochemically inert 3D CCC could essentially promote the energy density when calculating the entire electrode mass, along with long‐life cycle stability of 1000 cycles at 5C and no electrochemical corrosion on either anodes or cathodes. With an in situ optical microscope, the cathode expansion is found to massively reduce because the porous 3D CCC could effectively alleviate the huge volume. The results suggest a novel strategy for achieving low‐cost and high energy density DIBs with both mechanically and electrochemically stable features. Ultra‐lightweight 3D carbon current collectors are employed to construct all‐carbon electrodes used in dual‐ion batteries. The critical problems including metal corrosion, low mass ratio of active materials, and massive volume expansion in the cathodes based on metal current collectors are well addressed, promising a novel strategy for achieving high energy density batteries with both mechanically and electrochemically stable features.