Batteries and fuel cells for emerging electric vehicle markets

198

150

The century-old zinc-air (Zn-air) battery concept has been revived in the last decade due to its high theoretical energy density, environmental-friendliness, affordability, and safety. Particularly, electrically rechargeable Zn-air battery technologies are of great importance for bulk applications like electric vehicles, grid management, and portable electronic devices. Nevertheless, Zn-air batteries are still not competitive enough to realize widespread practical adoption because of issues in efficiency, durability, and cycle life. Here, following an introduction to the fundamentals and performance testing techniques, the latest research progress related to electrically rechargeable Zn-air batteries is compiled, particularly new key findings in the last five years (2013-2018). The strategies concerning the development of Zn and air electrodes are in focus. The design of other battery components, namely electrolytes and separators are also discussed. Poor performance of O electrocatalysts and the lack of the long-term stability of Zn electrodes and electrolytes remain major challenges. Finally, recommendations regarding the testing routines and materials design are provided. It is hoped that this up-to-date account will help to shape the future research activities toward the development of practical electrically rechargeable Zn-air batteries with extended lifetime and superior performance.

Section: Introductionmentioning

confidence: 99%

Recent Advances in Materials and Design of Electrochemically Rechargeable Zinc–Air Batteries

Chen

Zhou

Karahan

et al. 2018

198

150

“…The increasing demand for renewable energies, such as from solar and wind power, promotes the development of economically accessible and environmentally friendly energy storage systems . Batteries, especially lithium‐ion batteries (LIBs), are an ideal choice owing to their widespread application in consumer electronics and electric vehicles . However, the debate as to whether lithium resources can meet the growing demand has intensified owing to its low and complicated geographical availability in the Earth's crust .…”

Section: Introductionmentioning

confidence: 99%

CuO Nanoplates for High‐Performance Potassium‐Ion Batteries

Cao

Liu

et al. 2019

118

Potassium‐ion batteries (KIBs) are promising alternatives to lithium‐ion batteries because of the abundance and low cost of K. However, an important challenge faced by KIBs is the search for high‐capacity materials that can hold large‐diameter K ions. Herein, copper oxide (CuO) nanoplates are synthesized as high‐performance anode materials for KIBs. CuO nanoplates with a thickness of ≈20 nm afford a large electrode–electrolyte contact interface and short K+ ion diffusion distance. As a consequence, a reversible capacity of 342.5 mAh g−1 is delivered by the as‐prepared CuO nanoplate electrode at 0.2 A g−1. Even after 100 cycles at a high current density of 1.0 A g−1, the capacity of the electrode remains over 206 mAh g−1, which is among the best values for KIB anodes reported in the literature. Moreover, a conversion reaction occurs at the CuO anode. Cu nanoparticles form during the first potassiation process and reoxidize to Cu2O during the depotassiation process. Thereafter, the conversion reaction proceeds between the as‐formed Cu2O and Cu, yielding a reversible theoretical capacity of 374 mAh g−1. Considering their low cost, easy preparation, and environmental benignity, CuO nanoplates are promising KIB anode materials.

“…Thanks to high energy conversion efficiency and environmental friendliness, fuel cell technologies are recognized as a promising replacement to both traditional fossil fuel‐powered engines and currently popular electric vehicles . To date, hydrogen‐powered fuel cell is the most intensively studied type of fuel cells in both academic research and industries . However, hydrogen may not be an ideal energy fuel mainly because of the cost and safety concerns, which are related to its production, distribution, and storage.…”

Section: Direct Urea Fuel Cellsmentioning

confidence: 75%

Designing Advanced Catalysts for Energy Conversion Based on Urea Oxidation Reaction

Zhu

Liang

Zou

2020

353

270

Urea oxidation reaction (UOR) is the underlying reaction that determines the performance of modern urea‐based energy conversion technologies. These technologies include electrocatalytic and photoelectrochemical urea splitting for hydrogen production and direct urea fuel cells as power engines. They have demonstrated great potentials as alternatives to current water splitting and hydrogen fuel cell systems with more favorable operating conditions and cost effectiveness. At the moment, UOR performance is mainly limited by the 6‐electron transfer process. In this case, various material design and synthesis strategies have recently been reported to produce highly efficient UOR catalysts. The performance of these advanced catalysts is optimized by the modification of their structural and chemical properties, including porosity development, heterostructure construction, defect engineering, surface functionalization, and electronic structure modulation. Considering the rich progress in this field, the recent advances in the design and synthesis of UOR catalysts for urea electrolysis, photoelectrochemical urea splitting, and direct urea fuel cells are reviewed here. Particular attention is paid to those design concepts, which specifically target the characteristics of urea molecules. Moreover, challenges and prospects for the future development of urea‐based energy conversion technologies and corresponding catalysts are also discussed.