Recent advances in graphene-based materials for fuel cell applications

The unique chemical and physical properties of graphene and its derivatives (graphene oxide, heteroatom-doped graphene, and functionalized graphene) have stimulated tremendous efforts and made significant progress in fuel cell applications. This review focuses on the latest advances in the use of graphene-based materials in electrodes, electrolytes, and bipolar plates for fuel cells. The understanding of structure-activity relationships of metal-free heteroatom-doped graphene and graphene-supported catalysts was highlighted. The performances and advantages of graphene-based materials in membranes and bipolar plates were summarized. We also outlined the challenges and perspectives in using graphene-based materials for fuel cell applications

Degradation issues and stabilization strategies of protonic ceramic electrolysis cells for steam electrolysis

Protonic ceramic electrolysis cells (PCECs) are attractive electrochemical devices for converting electrical energy to chemicals due to their high conversion efficiency, favorable thermodynamics, fast kinetics, and inexpensive materials. Compared with conventional oxygen ion-conducting solid oxide electrolysis cells, PCECs operate at a lower operating temperature and a favorable operation mode, thus expecting high durability. However, the degradation of PCECs is still significant, hampering their development. In this review, the typical degradations of PCECs are summarized, with emphasis on the chemical stability of the electrolytes and the air electrode materials. Moreover, the degradation mechanism and influencing factors are assessed deeply. Finally, the emerging strategies for inhibiting long-term degradations, including chemical composition modifications and microstructure tuning, are explored

Thermo-photo catalytic anode process for carbonate-superstructured solid fuel cells

Converting hydrocarbons and greenhouse gases (i.e., carbon dioxide, CO2) directly into electricity through fuel cells at intermediate temperatures (450 to 550 °C) remains a significant challenge, primarily due to the sluggish activation of C-H and C=O bonds. Here, we demonstrated a unique strategy to address this issue, in which light illumination was introduced into the thermal catalytic CO2reforming of ethane in the anode as a unique thermo-photo anode process for carbonate-superstructured solid fuel cells. The light-enhanced fuel activation led to excellent cell performance with a record-high peak power density of 168 mW cm-2at an intermediate temperature of 550 °C. Furthermore, no degradation was observed during ~50 h operation. Such a successful integration of photo energy into the fuel cell system provides a new direction for the development of efficient fuel cells

Degradation issues and stabilization strategies of protonic ceramic electrolysis cells for steam electrolysis

Protonic ceramic electrolysis cells (PCECs) are attractive electrochemical de-vices for converting electrical energy to chemicals due to their high conversion efficiency, favorable thermodynamics, fast kinetics, and inexpensive materials. Compared with conventional oxygen ion- conducting solid oxide electrolysis cells, PCECs operate at a lower operating temperature and a favorable operation mode, thus expecting high durability. However, the degradation of PCECs is still significant, hampering their development. In this review, the typical degradations of PCECs are summarized, with emphasis on the chemical stability of the electrolytes and the air electrode materials. Moreover, the degradation mechanism and influencing factors are assessed deeply. Finally, the emerging strategies for inhibiting long- term degradations, including chemical composition modifications and microstructure tuning, are explored

Carbonate-superstructured solid fuel cells with hydrocarbon fuels

A basic requirement for solid oxide fuel cells (SOFCs) is the sintering of electrolyte into a dense impermeable membrane to prevent the mixing of fuel and oxygen for a sufficiently high open-circuit voltage (OCV). However, herein, we demonstrate a different type of fuel cell, a carbonate-superstructured solid fuel cell (CSSFC), in which in situ generation of superstructured carbonate in the porous samarium-doped ceria layer creates a unique electrolyte with ultrahigh ionic conductivity of 0.17 S.cm21 at 550 °C. The CSSFC achieves unprecedented high OCVs (1.051 V at 500 °C and 1.041 V at 550 °C) with methane fuel. Furthermore, the CSSFC exhibits a high peak power density of 215 mW.cm22 with dry methane fuel at 550 °C, which is higher than all reported values of electrolyte-supported SOFCs. This provides a different approach for the development of efficient solid fuel cells

Cost-effectiveness of analysis serplulimab plus chemotherapy as first-line therapy for PD-L1-positive advanced esophageal squamous cell carcinoma

ObjectiveOur study aimed to evaluate the cost-effectiveness of the addition of serplulimab to chemotherapy (cisplatin and fluorouracil) for programmed death-ligand 1 (PD-L1) positive advanced esophageal squamous cell carcinoma (ESCC) as the first-line treatment in China.MethodsA three-state Markov model was established to assess the incremental cost-effectiveness ratio (ICER) for serplulimab plus chemotherapy versus chemotherapy alone. Survival data were extrapolated from the ASTRUM-007 trial, cost data were derived from local sources, and utilities were derived from published literature. Health outcomes were measured as quality-adjusted life-years (QALYs). Sensitivity and probability sensitivity analyses were used to investigate the robustness of the model.ResultsIn the base-case analysis, compared with chemotherapy alone, serplulimab gained an additional 0.16 QALYs with an incremental cost of $29,547.88, leading to an ICER of$184,674.25/QALY. Additionally, the subgroup analyses presented that the ICERs of serplulimab plus chemotherapy were $157,892.50/QALY and$127,996.45/QALY in advanced ESCC patients with 1≤ CPS< 10 and CPS≥ 10, respectively. These ICERs significantly exceeded the Chinese willingness-to-pay (WTP) threshold. The deterministic sensitivity analysis illustrated that the cost of progression-free survival in serplulimab plus chemotherapy group was the parameter with the strongest influence on the ICERs.ConclusionIn the Chinese health care system, with 3 times China’s per capita gross domestic product as the WTP threshold, compared with chemotherapy alone, serplulimab combined chemotherapy is not economical for PD-L1-positive advanced ESCC in the first-line setting

CARBONATE-SUPERSTRUCTURED SOLID FUEL CELLS WITH HYDROCARBON FUELS

Solid oxide fuel cells (SOFCs) have gained prominence as high-efficiency electric generators, yet their high operating temperatures (\u3e800 oC) present challenges in terms of system cost, complexity, and long-term durability. Lowering the operating temperature to the low-temperature range (≤ 650 oC) has garnered significant attention, especially for utilizing hydrocarbons as fuels. However, the critical issue for low-temperature SOFCs is the polarization losses resulting from temperature reduction. This dissertation presents groundbreaking research on a novel fuel cell type known as the carbonate-superstructured solid fuel cell (CSSFC). A key innovation in CSSFCs lies in the in-situ generation of a eutectic carbonate phase (Li2CO3/Na2CO3) on the porous samarium-doped ceria (SDC). The interface between SDC and melted eutectic carbonates provides a fast transfer channel for oxygen ions and plugs the microchannels to prevent gas leakage, which enhances the oxygen ionic conductivity of solid electrolyte by 20-fold (from 3.5×10–3 to 7.3×10–2 S cm– 1), resulting in a six-fold increase in peak power density (PPD), reaching 215 mW cm–2 with dry methane fuel at 550 oC, surpassing all reported values of electrolyte-supported SOFCs. Furthermore, we integrated photo energy into the CSSFC system by introducing light illumination into the thermal catalytic CO2 reforming of ethane in the anode, creating a thermo-photo anode process for CSSFCs. Light-enhanced fuel activation leads to an outstanding cell performance, with a record peak power density of 168 mW cm−2 at 550 oC, with no observed degradation over ~50 hours of operation. Additionally, incorporating finer-scale gradient anode functional layers further enhances internal reforming reactions, reduces electrode polarization resistance, and increases PPD to 241 mW cm–2 at 550 oC with ethane fuels. The CSSFCs with gradient anodes maintain excellent durability with ethane fuels for over 200 hours. In conclusion, CSSFCs offer a promising platform for efficient electrochemical energy conversion with fuel flexibility, simplified fabrication, and reduced costs. These innovative developments in CSSFC technology, integration of photo energy, and anode design contribute significantly to advancing the field of low-temperature SOFCs and offer new prospects for sustainable energy generation

3D graphene: synthesis, properties, and solar cell applications

Three-dimensional (3D) graphene is one of the most important nanomaterials. This feature article highlights the advancements, with an emphasis on contributions from our group, in the synthesis of 3D graphene-based materials and their utilization in solar cells. Chemistries of graphene oxides, hydrocarbons, and alkali metals are discussed for the synthesis of 3D graphene materials. Their performances in dye-sensitized solar cells and perovskite solar cells (as counter electrodes, photoelectrodes, and electron extracting layers) were correlatively analyzed with their properties/structures (accessible surface area, electrical conductivity, defects, and functional groups). The challenges and prospects for their applications in photovoltaic solar cells are outlined

Progress in low-temperature solid oxide fuel cells with hydrocarbon fuels

Solid oxide fuel cells (SOFCs) are important electric generators due to their high energy efficiencies and fuel flexibilities. However, the high operation temperature (\u3e800 °C) results in high system cost/complexity and poor long-term durability. Recently, decreasing the operating temperature of SOFCs to the low-temperature range (≤650 °C) has attracted intensive attention, especially for the direct utilization of hydrocarbons as fuels. This review summarizes the latest progress in hydrocarbon fueled SOFCs working at ≤ 650 °C, mainly focusing on the challenges and strategies associated with electrolytes, anodes, and cathodes. It highlights the requirement for highly active and carbon/sulfur resistant anode and high ionic conductive electrolytes to gain a superior performance at a lower temperature