Poly L-lysine (PLL)-mediated porous hematite clusters as anode materials for improved Li-ion batteries

• Published in: Electronic materials letters Vol. 11; no. 5; pp. 815 - 821
• Main Authors: Kim, Kun-Woo, Lee, Sang-Wha
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.09.2015
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed Matter Physics; Materials Science; Nanotechnology; Nanotechnology and Microengineering; Optical and Electronic Materials; hematite; poly L-lysine; porous; Li-ion battery
• ISSN: 1738-8090; 2093-6788
• DOI: 10.1007/s13391-015-4504-4

Porous hematite clusters were prepared as anode materials for improved Li-ion batteries. First, poly-L-lysine (PLL)-linked Fe 3 O 4 was facilely prepared via cross-linking between the positive amine groups of PLL and carboxylate-bound Fe 3 O 4 . The subsequent calcination transformed the PLL-linked Fe 3 O 4 into porous hematite clusters (Fe 2 O 3 @PLL) consisting of spherical α-Fe 2 O 3 particles. Compared with standard Fe 2 O 3 , Fe 3 O 4 @PLL exhibited improved electrochemical performance as anode materials. The discharge capacity of Fe 2 O 3 @PLL was retained at 814.7 mAh g -1 after 30 cycles, which is equivalent to 80.4% of the second discharge capacity, whereas standard Fe 2 O 3 exhibited a retention capacity of 352.3 mAh g -1 . The improved electrochemical performance of Fe 2 O 3 @PLL was mainly attributed to the porous hematite clusters with mesoporosity (20–40 nm), which was beneficial for facilitating ion transport, suggesting a useful guideline for the design of porous architectures with higher retention capacity.