Al Doping for Mitigating the Capacity Fading and Voltage Decay of Layered Li and Mn‐Rich Cathodes for Li‐Ion Batteries. Issue 8 (2nd February 2016)

• Record Type: Journal Article
• Authors: Nayak, Prasant Kumar; Grinblat, Judith; Levi, Mikhael; Levi, Elena; Kim, Sangryun; Choi, Jang Wook; Aurbach, Doron
• Is Part Of: Advanced energy materials. Volume 6:Issue 8(2016)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-02-02
• Subjects: Al doping -- cycling stability -- Li‐ion batteries -- cathode materials -- voltage fading; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201502398
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract : Li and Mn‐rich layered cathodes, despite their high specific capacity, suffer from capacity fading and discharge voltage decay upon cycling. Both specific capacity and discharge voltage of Li and Mn‐rich cathodes are stabilized upon cycling by optimized Al doping. Doping Li and Mn‐rich cathode materials Li1.2 Ni0.16 Mn0.56 Co0.08 O2 by Al on the account of manganese (as reflected by their stoichiometry) results in a decrease in their specific capacity but increases pronouncedly their stability upon cycling. Li1.2 Ni0.16 Mn0.51 Al0.05 Co0.08 O2 exhibits 96% capacity retention as compared to 68% capacity retention for Li1.2 Ni0.16 Mn0.56 Co0.08 O2 after 100 cycles. This doping also reduces the decrease in the average discharge voltage upon cycling, which is the longstanding fatal drawback of these Li and Mn‐rich cathode materials. The electrochemical impedance study indicates that doping by Al has a surface stabilization effect on these cathode materials. The structural analysis of cycled electrodes by Raman spectroscopy suggests that Al doping also has a bulk stabilizing effect on the layered LiMO2 phase resulting in the better electrochemical performance of Al doped cathode materials as compared to the undoped counterpart. Results from a prolonged systematic work on these cathode materials are presented and the best results that have ever been obtained are reported. Abstract : Al doping is found to be useful in mitigating discharge voltage decay as well as stabilizing the specific capacity of Li and Mn‐rich cathode materials by suppressing layered‐to‐spinel transformation upon prolonged cycling. Al doped Li1.2 Ni0.16 Mn0.51 Al0.05 Co0.08 O2 is found to exhibit 96% capacity retention as compared to 68% for undoped Li1.2 Ni0.16 Mn0.56 Co0.08 O2 after 100 cycles.