Enhancing Electrochemical Performance of Stretchable Li-Ion Microbatteries by Tuning Microstructured Electrode Dimensions

Abstract

With the spectacular rise of wearable technologies, R&D on microbatteries is rapidly emerging on the world market. For example, smart electronic textiles require new features and battery designs that traditional battery technologies simply cannot provide. This has opened the door to innovation and added a new dimension to the global competition in battery research. 1 The potential sector that can be impacted includes Internet of Things (IoT), healthcare (skin patches, medical sensors, medical diagnostic devices), smart cards, etc. To date, the soft microbattery technology is still in its infancy because it requires the pooling of complementary knowledges in different scientific domains. Indeed, key competences in microelectronics, materials science, electrochemistry, polymer, and inorganic chemistry have to be gathered to overcome all technical challenges. Recently, we have reported a new concept for the development of stretchable Li-ion microbatteries. 2-4 A prototype has been also integrated in a scleral eye contact lens 5 . The innovative approach is based on the assembly of two flexible substrates comprising arrays of micro-pillars on serpentine current collectors that are separated by a polymer electrolyte. Besides achieving high areal capacity values like 2.5 mA h cm -2 at C/10 ( i.e., 0.07 mA cm -2 ), the micropillars make the system reversibly stretchable. Electrochemical tests revealed excellent performance when the stretchable micropower source was subjected to different mechanical strains. Indeed, 73% of the capacity is retained over 100 cycles under 30% strain and all fatigue tests showed that capacity retention remains higher than 70%. Preliminary results have shown the possibility to power low-consumption devices such as a light emitting diodes. It will be also discussed the parameters and treatments that have been investigated to increase the capacity and optimize the systems. 6 During this presentation, it will be also presented how to achieve the RF wireless charging of the battery. References [1] M. Nasreldin, S. de Mulatier, R. Delattre, M. Ramuz, T. Djenizian, Flexible and stretchable microbatteries for wearable technologies, Advanced Materials Technologies, Hall of Fame, 2000412 (2020). [2] T. Djenizian and R. Delattre, « Deformable accumulator », International Patent n° WO 2018/167393 A1, 20-sept-2018. [3] M. Nasreldin, R. Delattre, B. Marchiori, M. Ramuz, S. Maria, J. L. de Bougrenet de la Tocnaye, T. Djenizian, Microstructured electrodes supported on serpentine interconnects for stretchable electronics, APL Materials., 7, 031507 (2019). [4] M Nasreldin, R. Delattre, C. Calmes, M. Ramuz, V. A. Sugiawati, S. Maria, J-L de Bougrenet de la Tocnaye, T. Djenizian, High Performance Stretchable Li-ion Microbattery, Energy Storage Materials, 33, 108 (2020). [5] M. Nasreldin, R. Delattre, M. Ramuz, C. Lahuec, T. Djenizian and J-L de Bougrenet de la Tocnaye, Flexible Micro-Battery for Powering Smart Contact Lens, Sensors, 19, 2062 (2019). [6] A. Albertengo, M. Nasreldin, M. Ramuz, R. Delattre, D. Ochoa, M. Lepikhin, A. Galeyeva, F. Malchik, T. Djenizian, Advanced Materials Interfaces, 9, 2102541 (2022).