Enhancing the performance of Li/FeS2 battery

• Main Author: Wee, Ryan Zheng Sheng
• Other Authors: Hng Huey Hoon
• Format: Final Year Project
• Language: English
• Published: 2015
• Subjects: DRNTU::Science::Chemistry::Physical chemistry::Electrochemistry
• Online Access: http://hdl.handle.net/10356/63249
• Institution: Nanyang Technological University

Iron pyrite (FeS2) is an inexpensive and abundant material that has minimal environmental toxicity and high theoretical capacity. As such, it has already been tapped to make primary batteries commercially. Moreover, the usage of FeS2 as anode material has attracted more attention for usage in developing lithium ion secondary battery. However, there are still some intrinsic problems which caused the capacity of FeS2 to decrease to 4-8% of its original capacity after a number of charge-discharge cycles. To improve FeS2 cyclability, two investigations were carried out in this project. In the first investigation, 10wt% of additives such as nickel, carbon black, copper and cobalt powder were mixed with FeS2 to form the anode material. The FeS2/carbon black powders can sustain 33-42% of its cyclability (412mAhg-1), much higher than FeS2 prepared without carbon black (35mAhg-1). Copper, nickel and cobalt additives managed to retain 20-30% of the cyclability (276mAhg-1, 241mAhg-1 and 184mAhg-1 respectively). The second investigation aims to further improve the FeS2/carbon powders cyclability to a value higher than 33-42% range by decreasing FeS2 particle size towards submicron and nano range. Samples were planetary ball milled for 8, 12, 16, and 32 hours. Samples milled for 32hrs show the highest improvement by retaining 60% of their capacity.