The increasing energy storage demands of portable electronic devices and electric vehicles leads to the development of high performance lithium-ion batteries. Current technologies cannot reach the power and energy density requirements. More attention has been paid to the development of new electrode materials and electrolytes but performance continues to be limited. The strategy is to develop a 3D battery architecture. The planar configuration is locally reproduced within a 3D matrix. The surface area is increased and the distance between electrodes is reduced. Prieto, a start-up based in Colorado, proposed this new architecture in 2013. They have obtained a 3D anode/electrolyte configuration. However, complete integrated 3D battery shows fast cyclability failure due to the cathode configuration.

Our strategy is to start by the cathode. A metallic foam is used as the current collector and as the 3D matrix. A new synthesis to produce an optimized Li-ion cathode for this new battery configuration is presented. Either native metal, or the corresponding oxides, can be used as precursors for the synthesis of the lithiated transition metal oxides. The metallic surface is first oxidised and then lithiated. Alternatively, the metal surface can be directly lithiated. In both cases, the current collector, is directly furnished with active material without the need of either binders or conductive additives. Structural characterization was coupled with morphological analysis to understand the influence of oxide morphology on the synthesis and the lithiation mechanism. In addition, electrochemical characterizations will be presented.

A polymer electrolyte was then grafted directly to the cathode surface using electrochemical polymerisation. Electrochemical grafting enables the formation of a uniform, thin polymer electrolyte. A better electrode/electrolyte interface is obtained and ionic resistance are minimised. Furthermore, the porosity of the foam is available for anode materials. The effect of polymerization parameters of monomer concentration, solvent, applied potential and scanning rate were studied.

The foam porosity was filled with a low melting point metal that is used both as the anode and the current collector. Electrochemical characterization of this new configuration allows the assessment of the performance gain of this new architecture for lithium-ion batteries. Analysis of the battery interfaces (electrode/electrolyte, electrode/current collector) provide further insight into their influence on battery performance.