US Patent 9362551 Reinforced battery electrodes

The gravimetric and volumetric efficiency of lithium ion batteries may be increased if high capacity materials like tin and silicon may be employed as the lithium-accepting host in the negative electrode of the battery. But both tin and silicon, when fully charged with lithium, undergo expansions of up to 300% and generate appreciable internal stresses which have potential to spall off material from the electrode on each discharge-charge cycle, resulting in a progressive reduction in battery capacity, also known as battery fade. A method of reinforcing such electrode materials by incorporating within them fiber reinforcements or shaped, elongated reinforcements fabricated of shape memory alloy is described. Electrode materials incorporating such reinforcements are less prone to damage under applied stress and so less prone to battery fade.