High energy density flexible and ecofriendly lithium-ion smart battery

The rapidly growing battery market demands both high energy density and waste-management solutions for the anticipated global annual battery waste of about two million metric tons. To address the energy-environment dilemma, we developed self-standing composite electrodes for Li-ion batteries without electrochemically inactive metal current collectors, additives, and binders, increasing energy density by up to 40%. The electrodes were prepared via in situ mixing of as-grown single-wall carbon nanotubes (SWNTs) with aerosolized electrode active materials, leading to adequate electrical conductivity and mechanical robustness. The SWNT scaffold exhibits a piezoresistive effect, with resistance depending on the voltage-weighted number of inter-nanotube contacts. We exploit this intrinsic piezoresistance of SWNT network for operando self-monitoring of battery structural health. The proposed solution-free battery fabrication technology and architecture eliminates environmentally harmful components and enables recycling by simple mechanical separation, aiming at safety and circular economy.