Community Research and Development Information Service - CORDIS

FP7

LiCrystG Result In Brief

Project reference: 331476
Funded under: FP7-PEOPLE
Country: Germany

New light on cathode materials for next-generation batteries

Batteries using olivine-type lithium-ion phosphate cathodes give a much desired combination of long life, high power density and stable operation in high temperatures. EU researchers shed further light into these not-so-ordinary lithium compounds to accelerate full-scale entry into the battery market.
New light on cathode materials for next-generation batteries
The crystal structure of olivine-type lithium-ion phosphates is very stable, making them display excellent thermal stability even at high temperatures. Other major commercial advantages are that they do not have safety concerns such as overheating and explosion, and they have longer lifetimes and higher power density. Interest in olivine phosphates has also been revived by the recent discovery of unusual ferrotoroidic domains that may be the key to speeding up data storage.

Single crystals of this promising class of materials are extremely rare, mainly because of lithium's high volatility. Within the LICRYSTG (Single-crystalline lithium-based model systems of future materials for electrochemical energy storage and data storage) project, scientists provided some of the missing single crystals as well as experimental data that enables further understanding on what makes them the next-generation cathode materials.

The team successfully grew high-quality single crystals of different lithium compounds to further study anisotropy and ferrotoroidicity. Anisotropic lithium diffusion along the various crystallographic directions can help develop theoretical models on battery performance and ageing. A travelling solvent floating zone technique allowed single-crystal growth of lithium-based systems under external pressure of 150 bar.

Researchers' work on manganese-induced local disorder in lithium manganese phosphate showed why the manganese-based olivine exhibits relatively poor electrochemical properties. Thermal expansion and magnetostriction studies provided information on the structural changes and magnetoelastic coupling. These data were supported by specific heat and magnetisation studies that provided further information on the crystal quality and electronic properties. In addition, the team provided the magnetic phase diagrams. For selected crystals, diffusion parameters of anisotropic lithium diffusion along the main crystallographic axes were determined.

Spectroscopy studies on lithium cobalt phosphate provided information on short-range magnetic ordering at high temperatures.

Project results offer valuable information for optimising and tailoring nano- and micro-structured lithium-ion battery materials, helping Europe take the lead in cutting-edge battery technologies.

Related information

Keywords

Cathode, batteries, olivine, lithium-ion phosphate, single crystals, lithium diffusion
Record Number: 183023 / Last updated on: 2016-07-18
Domain: Energy