Additive Manufacturing as a Means of Gas Sensor Development for Battery Health Monitoring

Lithium-ion batteries (LIBs) still need continuous safety monitoring based on their intrinsic properties, as well as due to the increase in their sizes and device requirements. The main causes of fires and explosions in LIBs are heat leakage and the presence of highly inflammable components. Therefore, it is necessary to improve the safety of the batteries by preventing the generation of these gases and/or their early detection with sensors. The improvement of such safety sensors requires new approaches in their manufacturing. There is a growing role for research of nanostructured sensor’s durability in the field of ionizing radiation that also can induce structural changes in the LIB’s component materials, thus contributing to the elucidation of fundamental physicochemical processes; catalytic reactions or inhibitions of the chemical reactions on which the work of the sensors is based. A current method widely used in various fields, Direct Ink Writing (DIW), has been used to manufacture heterostructures of Al2O3/CuO and CuO:Fe2O3, followed by an additional ALD and thermal annealing step. The detection properties of these 3D-DIW printed heterostructures showed responses to 1,3-dioxolan (DOL), 1,2-dimethoxyethane (DME) vapors, as well as to typically used LIB electrolytes containing LiTFSI and LiNO3 salts in a mixture of DOL:DME, as well also to LiPF6 salts in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC) at operating temperatures of 200 °C–350 °C with relatively high responses. The combination of the possibility to detect electrolyte vapors used in LIBs and size control by the 3D-DIW printing method makes these heterostructures extremely attractive in controlling the safety of batteries

ANNEALING EFFECT ON UV DETECTION PROPERTIES OF ZnO:Al STRUCTURES

The aim of this study was to develop low-powered, highly selective UV sensor to continuously monitor personalized UV exposure as well as to study annealing effect on UV detection properties of the sensors. ZnO:Al structures were obtained by chemical growth method followed by thermal annealing at 625 °C for 2 h. The studied samples exhibit maximal UV response of 620/488 at 25 °C/50 °C to 370 nm UV radiation before/after annealing, respectively. Thermal annealing of sensor (250 °C for 1 h) led to improvement in fall time from 3860 seconds to 262 seconds at 25 °C and highest responsivity (~48 mA/W) came out for 370 nm wavelength at 75 °C operating temperatures. Consequently, excellent selectivity for 370 nm UV illumination can be ascribed as due to thermal annealing effect which increases the crystallinity, grain size, and roughness of the sensing film. The PL measurements reveals the suppression of structural defects, increase in intensity after annealing and enhanced UV response due to presence of Al content in films. Overall, these structures showed magnificent UV properties, before and especially after additional thermal annealing. UV sensing mechanism of such nanomaterial-based sensor were explained with physio-chemical processes take place on the surface of these structures. The obtained results on annealed ZnO:Al films-based devices is superior to reported performances of other nanostructures, proving new results for UV sensing applications at different operating temperatures in various fields