Marie Francine Lagadec

A consortium-wide survey in NCCR Catalysis reveals a sociotechnical bottleneck in integrating sustainability into day-to-day chemical research and identifies practical levers to overcome it.

Curious about how chemistry can contribute to sustainable development? In this overview, we explain the essence of NCCR funding, the research focus and structural goals of NCCR Catalysis, and how these align with the sustainable development goals (SDGs). Additionally, we highlight opportunities for getting involved with our program.

Green hydrogen production using renewables-powered, low-temperature water electrolysers is crucial for rapidly decarbonizing the industrial sector and with it many chemical transformation processes. However, despite decades of research, advances at laboratory scale in terms of catalyst design and insights into underlying processes have not resulted in urgently needed improvements in water electrolyser performance or higher deployment rates. In light of recent developments in water electrolyser devices with modified architectures and designs integrating concepts from Li-ion or redox flow batteries, we discuss practical challenges hampering the scaling-up and large-scale deployment of water electrolysers. We highlight the role of device architectures and designs, and how engineering concepts deserve to be integrated into fundamental research to accelerate synergies between materials science and engineering, and also to achieve industry-scale deployment. New devices require benchmarking and assessment in terms of not only their performance metrics, but also their scalability and deployment potential.

Pore space connectivity is a useful metric for describing microstructure of lithium ion battery components.

In this paper, we study how polyolefin separators respond to compressive stress, which can occur during battery operation as active particles lithiate, expand, and push into and deform the separator. We use real microstructures of polyethylene and polypropylene separators acquired with focused ion beam scanning electron microscopic (FIB-SEM) tomography and simulate how these structures deform under compressive strain. After validating our mechanical simulations, we characterize how the microstructural properties of the separators change as a function of compressive strain and simulate the influence these changes in microstructure have on the lithium ion transport through the separator. We find that a given compressive strain negatively impacts the microstructure of polyethylene separator more than that of a polypropylene separator. To understand the origins of the different response to compressive strains in polyethylene and polypropylene separators, we use a network-based analysis to assess the type of mechanical deformations occurring in the separator membrane and show that it is the combination of material properties and structure that are responsible for the greater stability of polypropylene. This work highlights how the structure of a separator plays an important role in its mechanical robustness and prevention of cell degradation.

Measuring radiation dosage rates is becoming more and more important in many applications scenarios. Continuously monitoring radiation in contaminated and poorly accessible areas is challenging due to the frequent data collection/transmission combined with long life requirements. We present a self-sustainable wireless sensor node for low power, high precision radiation dosage rate monitoring. We propose an energy-efficient data acquisition algorithm that can reduce the energy per measurement, while guaranteeing minimal loss of precision. The proposed node is designed to work in collaboration with an unmanned aerial vehicle used for two essential mission steps: air-deployment of the wireless sensor nodes at suitable locations, and acquiring data logs via low-power, shortrange radio communication in fly-by mode after a wake-up command. The system uses off-the-shelf components for defining the mission, drop-zone, and trajectory, for compressing data and managing communication. The node is equipped with a novel low-power nuclear radiation sensor, and has been designed and implemented with self-sustainability in mind as it will be deployed in hazardous, inaccessible areas. To this end, the proposed node uses a combination of complementary techniques: a low-power microcontroller with non-volatile memory, energy harvesting, adaptive power management, and a nano-watt wake-up radio. Experimental results demonstrate the precision and the low energy consumption of the radiation sensor, the energy efficiency of the whole solution, and the acquisition algorithms. The node consumes only 31μW in sleep mode and 1.7mW in active mode, and has the capability to achieve perpetual monitoring once deployed.

The microstructure of lithium ion battery separators plays an important role in separator performance; however, here we show that a geometrical analysis falls short in predicting the lithium ion transport in the electrolyte-filled pore space. By systematically modifying the surface chemistry of a commercial polyethylene separator while keeping its microstructure unchanged, we demonstrate that surface chemistry, which alters separator-electrolyte interactions, influences ionic conductivity and lithium ion transference number. Changes in separator surface chemistry, particularly those which increase lithium ion transference numbers can reduce voltage drops across the separator and improve C-rate capability.