Energy-storage multifunctional composites

This work investigated the design, construction, engineering, manufacture and properties of energy-storage multifunctional composites. The construction of a prototype energy-storage structure is demonstrated, its properties investigated and reported. Multifunctional materials are a new type of advanced materials combining additional functions with the traditional load-bearing single role performed by classical structural materials in order to save space and weight. A successful energy storage structure must satisfy the following two requirements as a minimum: (1) the embedded energy cell is still able to charge and discharge equally as well as before embedding and also under mechanical loading, and (2) the energy storage structure is able to maintain adequate mechanical performance. We demonstrate that such an energy storage structure is possible.;The approach employed in this work consisted of using readily available commercial off-the-shelf components (COTS) such as thin-film lithium energy cells and carbon fiber reinforced plastic (CFRP) composites. The new constraints imposed by the design, engineering and manufacturing process on each element of the new structure hence obtained, and the new characteristic physical, electrical and mechanical properties realized in the final structure were investigated and are reported.;These structures were assembled and integrated within the confines of a multifunctional structural composite in order to save weight and space. Carbon fiber reinforced plastic (CFRP) composites were laminated with energy storage all-solid-state thin-film lithium cells. The processes of physically embedding all-solid-state thin-film lithium energy cells into carbon fiber reinforced plastics (CFRPs) and the approaches used are reported. The effects of uniaxial tensile loading on the embedded structure were investigated and reported. The mechanical, electrical and physical aspects of energy harvesting and storage devices incorporated into composite structures are discussed. Embedding all-solid-state thin-film lithium energy cells into CFRPs did not significantly alter the CFRP mechanical properties (yield strength and Young's modulus). The CFRP embedded energy cells performed at baseline charge/discharge levels up to a loading of about 50% of the ultimate CFRP uniaxial tensile rupture loading.;Multifunctional energy storage composite power structures developed in this work were investigated under constant amplitude uniaxial tensile sinusoidal harmonic dynamic loadings. The multifunctional composites were also able to store electrical energy in addition to the more traditional unifunctional role of structural load bearing. Thin-film energy cells were embedded in the confines of CFRP composite structures and subjected to uniaxial tensile sinusoidal harmonic loading fatigue cycling while undergoing charge and discharge cycles. Fatigue baselines were established for test coupons both with and without embedded energy cells, as well as baselines for the energy cells before and after embedding. The electrical charge and discharge performance of the resulting energy storage multifunctional composite under mechanical dynamic fatigue loading was within baseline parameters up to 100 fatigue cycles at 150 MPa. For over 1,000 fatigue cycles, the capacities found were below minimum baseline parameters.