University:
Boston University
Course:
CAS CH 195 | Freshman Seminar in the Chemical Sciences
Academic year:

2022
Views:

259

Pages:

9
Author:

SpaceCadet101

Reversible solid oxide cells for improving gridscale renewable energy implementation Reversible solid oxide cells Project goals 1. Microstructure evolution during operation • Characterizing cell microstructure and performance degradation 2. Costs of RSOC implementation and scale-up • Costs of novel electrode microstructures • Remaining obstacles to RSOC adoption Microstructure evolution during operation • Oxygen electrode is stable over 500hrs of operation NNO NNO/ NDC50 GDC10 YSZ 𝑵𝒅𝟐 𝑵𝒊𝑶𝟒 → 𝑵𝒅𝟐 𝑶𝟑 + 𝑵𝒊𝑶 Microstructure evolution during operation • Fuel electrode degradation occurs due to loss of active reaction sites 1. Loss of connected Ni phase 2. Coarsening of connected Ni phase Change in connected Ni fraction (%) Change in connected Ni particle size (%) Untested Uninfiltrated SOEC Infiltrated SOEC -2.65 -23.15 -18.44 -2.22 20.77 5.17 • GDC-infiltration mitigates both these degradation behaviors Images collected by Emily Ghosh Costs of RSOC implementation and scale-up • Compared energy costs of materials and processing for conventional and novel oxygen electrode Oxygen electrode material Total Energy Cost (MJ/Kg) Electrolysis current density (Acm-2) Fuel cell current density (Acm-2) LSM-YSZ 235 0.085 0.1 LSCF-CGO 478 1.08 0.93 NNO-NDC50 446 1.67 1.31 Database: Granta, Jung et al. (2016), Akter et al. (2022) Costs of RSOC implementation and scale-up Material Critical list? Abundance risk Environmental country risk Sourcing and geopolitical risk Main sources Gd US and EU Medium Very high Very high China, US, Russia, India Ce US and EU Medium Very high Very high China, US, Russia Australia, Russia, Canada, Indonesia, Philippines China, US, India Spain, China Congo, Canada, China China China, US, India Ni None Medium Very low Very low Nd Sr US and EU US and EU Medium Low Very high Medium Very high High Co US and EU Medium Low Medium Fe La None US and EU Very low Medium Low Very high Low Very high Mn US Low Very low Very low Australia, Brazil, South Africa Y US and EU Medium Very high Very high China Zr US Low Very low Very low Australia, South Africa, China Database: Granta Costs of RSOC implementation and scale-up Performance and efficiency • Stability: current technologies have shown potential lifetimes up to 40,000h (Bosio 2023) • Cost: Commercial targets require 80,000hr+ to be competitive (Bosio 2023) Implementation • Load following capability (Baldinelli 2019) • High initial investment and public opinion (Salim 2022) • Optimizing system management (Bianchi 2023) • Thermal energy consumption and balance (Min 2022, Bianchi 2021) Durability and system lifetime remains largest barrier Future directions Challenges • Sample preparation and training on new instrumentation • Long test times and large sample size requirements • Accounting for lab-scale vs. industry scale production of electrodes Future work • 3D reconstruction characterization • Continuing characterization with TEM • Communicating and visualizing the challenges of renewable energy intermittency