Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals

Technology #16027

Questions about this technology? Ask a Technology Manager

Download Printable PDF

Image Gallery
Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals 1Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals 2Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals 3Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals 4Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals 5Multi-Electron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals 6
Categories
Inventors
Professor Gerbrand Ceder
Department of Materials Science and Engineering, MIT
External Link (web.mit.edu)
Geoffroy Hautier
Department of Materials Science and Engineering, MIT
Jain Anubhav
Department of Materials Science and Engineering, MIT
Timothy Mueller
Department of Materials Science and Engineering, MIT
Managed By
Christopher Noble
MIT Technology Licensing Officer - Clean and Renewable Energy
Patent Protection

Design of Multi-Electron Li-Ion Phosphate Cathodes by Mixing Transition Metals

PCT Patent Application WO 2014-110412

Design of Multi-Electron Li-Ion Phosphate Cathodes by Mixing Transition Metals

US Patent Pending 2014-0246619
Publications
Designing Multielectron Lithium-Ion Phosphate Cathodes by Mixing Transition Metals
Chemistry of Materials, April 24, 2013, p.2064

Applications

This technology can be applied to lithium-ion batteries to increase energy capacity.

Problem Addressed

Current phosphate-based lithium-ion batteries typically store one lithium ion per transition metal in the cathode, which intrinsically limits the cathode's maximum energy density.  Multi-electron cathodes, where more than one lithium ion can be cycled per transition metal, would drastically increase battery capacity.  Many transition metals have multiple stable oxidation states and could, in theory, be used as multi-electron cathodes.  However, activating the additional redox reactions in the metal typically require voltages that are not suitable for commercial batteries.  This technology uses two different metals to create stable multi-electron cathodes that operate within voltage ranges that are practical for commercial applications.

Technology

Lithium ion batteries operate by reversibly inserting and removing lithium ions from the cathode material.  In theory, many cathode structures can accommodate metal cations with reduction states of +2, +3, and +4 so each metal can participate in multiple redox reactions, creating multi-electron cathodes.  However, there is no transition metal where both the +2/+3 and the +3/+4 redox couple are active within the appropriate voltage range for commercial batteries so, currently, only one redox couple can be used in the battery operation.  This technology mixes molybdenum or vanadium with another transition metal using the overall formula LiaMxM'yX, where M is one or more transition metals, M' is molybdenum and/or vanadium, and X is a chemical group that contains phosphate.  Mixing a transition metal M that has a high +2/+3 redox voltage with molybdenum or vanadium combines the redox couples of the different metals and allows more than one lithium ion to be stored per metal, which increases the cathode capacity over using any of the metals alone.

Advantages

  • Higher capacity lithium-ion batteries
  • Compatible with current commercially used electrolytes