3D Printed High‐Performance Lithium Metal Microbatteries Enabled by Nanocellulose

• Published in: Advanced materials (Weinheim) 2019-04, Vol.31 (14), p.e1807313-n/a
• Main Authors: Cao, Daxian, Xing, Yingjie, Tantratian, Karnpiwat, Wang, Xiao, Ma, Yi, Mukhopadhyay, Alolika, Cheng, Zheng, Zhang, Qing, Jiao, Yucong, Chen, Lei, Zhu, Hongli
• Format: Article
• Language: English
• Subjects: 3-D printers; 3D printing; Anodes; Biopolymers; cellulose nanofibers; dendrite; Dendritic structure; Density functional theory; electrical conductivity; Lithium; Lithium batteries; lithium metal batteries; Local current; Materials science; Microbatteries; Miniaturization; Nanofibers; Prototyping; Scaffolds; Shear thinning (liquids); Three dimensional printing; viscosifier
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201807313

Batteries constructed via 3D printing techniques have inherent advantages including opportunities for miniaturization, autonomous shaping, and controllable structural prototyping. However, 3D‐printed lithium metal batteries (LMBs) have not yet been reported due to the difficulties of printing lithium (Li) metal. Here, for the first time, high‐performance LMBs are fabricated through a 3D printing technique using cellulose nanofiber (CNF), which is one of the most earth‐abundant biopolymers. The unique shear thinning properties of CNF gel enables the printing of a LiFePO4 electrode and stable scaffold for Li. The printability of the CNF gel is also investigated theoretically. Moreover, the porous structure of the CNF scaffold also helps to improve ion accessibility and decreases the local current density of Li anode. Thus, dendrite formation due to uneven Li plating/stripping is suppressed. A multiscale computational approach integrating first‐principle density function theory and a phase‐field model is performed and reveals that the porous structures have more uniform Li deposition. Consequently, a full cell built with a 3D‐printed Li anode and a LiFePO4 cathode exhibits a high capacity of 80 mA h g−1 at a charge/discharge rate of 10 C with capacity retention of 85% even after 3000 cycles. High‐aspect ratio lithium metal batteries are enabled through a 3D printing technique using nanocellulose from trees as ink surfactant, viscosifier, and conductive scaffold. The full cell achieves a high reversible capacity of 80 mAh g–1 at 10 C and remains stable for over 3000 cycles with high capacity retention of 85%.