Details of Grant 

EPSRC Reference:	EP/H036199/1
Title:	Computer modelling of nano-materials for negative electrodes in Li-ion batteries
Principal Investigator:	Alfredsson, Dr LM
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department:	Sch of Physical Sciences
Organisation:	University of Kent
Scheme:	First Grant - Revised 2009
Starts:	23 September 2010	Ends:	22 September 2012	Value (£):	72,491
EPSRC Research Topic Classifications:	Energy Storage Materials Characterisation
EPSRC Industrial Sector Classifications:	Energy
Related Grants:
Panel History:	Panel Date Panel Name Outcome 25 Feb 2010 Physical Sciences Panel - Materials Announced
Summary on Grant Application Form
Lithium-ion batteries have found an important place in our daily life, used in portable electrical devices e.g. mobile phones and laptops. Despite their success they are still open for improvement, particularly if their applications should be extended to hybrid (HEV) and electrical vehicles (EV). The batteries currently available on the market show problems with capacity (energy density), cell-potential, charge/discharge rates and lifetime. In (most) commercial Li-ion batteries on the market today, the technology in both the anode and cathode materials are based on classical Li-intercalation processes, where Li-ions are extracted or inserted from an open host structure. The disadvantages with these materials are their failure to often incorporate more than one Li-ion per transition metal (TM) ion, resulting in low capacity (energy density).The introduction of nano-materials in the field of Li-ion batteries has re-opened the investigations on simple transition metal oxides, sulphides, and nitrides as attractive new anode materials. Experiments show that the reactions of these TM compounds with Li are different from the classical Li-intercalation processes. Instead the transition metals are reduced in the presence of Li-ions to form metal nano-particles of 2 to 8 nm in size, dispersed in a Li2X (X=O, S or N) matrix. Owing to the fact that the Li/TM ratio associated with these reactions are larger than one, these materials show high energy storage; in some materials above 1000 mAh/g, which is about three times as high as in commercial graphite anodes. However, the capacity associated with conversion reactions often decrease rapidly after the first charge/discharge cycle. Hence, to improve the properties of these materials we need to characterise these reactions in detail on an atomic level.One powerful tool, to gain atomic information is the combination of first-principles and classical inter-atomic potential simulations. Here we propose to use such an arrangement to determine the stability and reactivity of TM-oxide nano-particles (2-8 nm) investigated as potential anode materials in conversion reactions. The theories we will apply are well established in the field of battery modelling and material science, but they have rarely or never been applied to conversion reactions of nano-particles before. The calculations will, therefore, partly be guided by collaboration with experimental groups studying the corresponding systems. For this purpose we need to study a system that is well documented, and that we have experience synthesising and characterising here in Kent. The material should, of course, also have the potential as an anode material in Li-ion batteries. Fe3O4 satisfies the requested criterions. Further, Fe3O4 is highly available (low cost) and non-toxic. The PI has expertise in modelling iron-bearing materials, using both first principles and classical inter-atomic potential techniques. We will establish the energetically most stable Fe3O4 nano-particle structures as a function of Li-ion concentration and particle size, allowing us to also calculate the cell voltage of the material. The rate and power capability of the material can be understood by determining the Li-ion reactivity and band gap of the particles, respectively.
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Organisation Website:	http://www.kent.ac.uk