Why social values cannot be changed for the sake of conservation

The hope for creating widespread change in social values has endured among conservation professionals since early calls by Aldo Leopold for a “land ethic.” However, there has been little serious attention in conservation to the fields of investigation that address values, how they are formed, and how they change. We introduce a social–ecological systems conceptual approach in which values are seen not only as motivational goals people hold but also as ideas that are deeply embedded in society’s material culture, collective behaviors, traditions, and institutions. Values define and bind groups, organizations, and societies; serve an adaptive role; and are typically stable across generations. When abrupt value changes occur, they are in response to substantial alterations in the social–ecological context. Such changes build on prior value structures and do not result in complete replacement. Given this understanding of values, we conclude that deliberate efforts to orchestrate value shifts for conservation are unlikely to be effective. Instead, there is an urgent need for research on values with a multilevel and dynamic view that can inform innovative conservation strategies for working within existing value structures. New directions facilitated by a systems approach will enhance understanding of the role values play in shaping conservation challenges and improve management of the human component of conservation

Ultra-high areal capacity Li electrodeposition at metal-solid electrolyte interfaces under minimal stack pressures enabled by interfacial Na-K liquids

The need for higher energy density rechargeable batteries has generated interest in metallic electrodes paired with solid electrolytes. However, impedance growth at the Li metal-solid electrolytes interface due to void formation during cycling at practical current densities and areal capacities, e.g., greater than 0.5 mA cm-2 and 1.5 mAh cm-2 respectively, remains a significant barrier. Here, we show that introducing a wetting interfacial film of Na-K liquid between Li metal and Li6.75La3Zr1.75Ta0.25O12 (LLZTO) solid electrolyte permits reversible stripping and plating of up to 150μm of Li (30 mAhcm-2), approximately ten times the areal capacity of today’s lithium-ion batteries, at current densities above 0.5 mA cm-2 and stack pressures below 75 kPa, all with minimal changes in cell impedance. We further show that this increase in the accessible areal capacity at high stripping current densities is due to the presence of Na-K liquid at the Li stripping interface; this performance improvement is not enabled in the absence of the Na-K liquid. This design approach holds promise for overcoming interfacial stability issues that have heretofore limited performance of solid-state metal batteries

Controlling dendrite propagation in solid-state batteries with engineered stress

Metal dendrite penetration is a mode of electrolyte failure that threatens the viability of metal anode based high energy solid-state batteries. Whether dendrites are driven by mechanical failure or electrochemical degradation of solid electrolytes remains an open question. If internal mechanical forces drive failure, superimposing an external compressive load that counters internal stress may mitigate dendrite penetration. Here, we investigate this hypothesis by dynamically applying mechanical loads to growing lithium metal dendrites in Li6.75La3Zr1.75Ta0.25O12 solid electrolytes. Operando microscopy reveals marked deflection in the dendrite growth trajectory at the onset of compressive loading. At loads near 200 MPa, this deflection is sufficient to avert cell failure. Using fracture mechanics, we quantify the impact of stack pressure and in-plane stresses on dendrite trajectory, chart the residual stresses required to prevent short-circuit failure, and propose cell design approaches to achieve such stresses. The model and experiments show that in the materials studied here, dendrite propagation is dictated by fracture of the electrolyte and that electronic conductivity plays a negligible role

The impact of pulsed current waveforms on Li dendrite initiation and propagation in solid-state Li batteries

Lithium dendrites are amongst the key challenges hindering Solid-State Li Batteries (SSLB) from reaching their full potential in terms of energy and power density. The formation and growth of these dendrites cause an inevitable failure at charge rates far below the threshold set by industry (>5 mA/cm2) and are supposedly caused by stress accumulation stemming from the deposited lithium itself. Herein, we demonstrate that MHz pulsed currents can be used to increase the current density by a factor of six, reaching values as high as 6.6 mA/cm2 without forming Li dendrites. To understand the origin of this improvement we propose an extension of previous mechanisms by considering the Li activity as a critical factor. The Li activity becomes relevant when Li is geometrically constrained, and the local plating rate exceeds the exchange current density. Over a critical Li activity, the solid-state electrolyte close to the tip of the dendrite fractures and releases the accumulated elastic energy. These events deteriorate the functional and mechanical performance of the SSLB. Since the buildup of a critical Li activity requires a certain time, the application of current pulses at shorter time scales can be used to significantly improve the rate-performance of SSLB, representing a potential step towards the practical realization of electric vehicles and other emerging applications

Semi-solid alkali metal electrodes enabling high critical current densities in solid electrolyte batteries

The need for higher energy-density rechargeable batteries has generated interest in alkali metal electrodes paired with solid electrolytes. However, metal penetration and electrolyte fracture at low current densities have emerged as fundamental barriers. Here we show that for pure metals in the Li–Na–K system, the critical current densities scale inversely to mechanical deformation resistance. Furthermore, we demonstrate two electrode architectures in which the presence of a liquid phase enables high current densities while it preserves the shape retention and packaging advantages of solid electrodes. First, biphasic Na–K alloys show K critical current densities (with the K-β″-Al O electrolyte) that exceed 15 mA cm . Second, introducing a wetting interfacial film of Na–K liquid between Li metal and Li La Zr Ta O solid electrolyte doubles the critical current density and permits cycling at areal capacities that exceed 3.5 mAh cm . These design approaches hold promise for overcoming electrochemomechanical stability issues that have heretofore limited the performance of solid-state metal batteries. + ‒2 ‒2 2 3 6.75 3 1.75 0.25 1

Damage relief of ion-irradiated Inconel alloy 718 via annealing

Inconel alloy 718 is a high-strength and corrosion resistant alloy that is commonly used as a beamline vacuum window. The accumulation of irradiation-induced damage substantially decreases the window's service lifetime, and replacing it engenders significant beamline downtime. With this application in mind, herein we examine whether post-irradiation annealing can alleviate irradiation-induced damage of Inconel alloy 718. Inconel alloy 718 was received in a solution annealed state. We then irradiated samples using two different modalities (1.5 MeV H+ and 5 MeV Ni2+) at three representative temperatures for beamline windows (room temperature, 100 degrees C, and 200 degrees C), followed by annealing at temperatures viable for in-situ annealing processes (no anneal, 300 degrees C, and 500 degrees C). Using nanoindentation, we determined that irradiation-induced hardening occurs but is largely mitigated by post-irradiation annealing. Overall, our results suggest that in-situ annealing of radiation damage in Inconel alloy 718 vacuum windows appears feasible, which could potentially decrease beam downtime and maintenance costs