Development/characterization of materials for electrochemical energy storage

公众对温室气体排放造成的全球气候变化的认识已导致风能和太阳能等可再生能源的利用增加，而且还将进一步增加。这些能源本质上是间歇性的，需要有效的方法来储存电力以供以后使用。高效的电化学储能装置是采用这些替代能源的关键部件。EES装置是用来储存化学能的媒介，这些化学能可以在以后转化为电能。电池存储是提供存储的一种方式，尽管能量也可以通过电解水以氢的形式存储。EES设备的开发和商业化受到一些材料工程问题的限制，这些问题与这些设备的制造、操作和长期可靠性有关。拟议的研究计划将集中于用于EES应用的新材料的开发和表征，重点是两种类型的器件，锌离子电池(ZIB)和固体氧化物电解槽(SOEC)。 固体氧化物燃料电池(SOFC)是将化学能转化为电能的装置。典型的燃料是氢(虽然也可以使用其他燃料)，它在阳极处被氧化成水，释放出电子。SOEC本质上是反向操作的SOFC。这两者可以组合在一个设备中，称为固体氧化物电池(SOC)。通常，氢电极是由氧化钇稳定的氧化锆(YSZ)和镍(Ni)组成的金属陶瓷。限制该电极商业化应用的问题之一是该电极的长期稳定性。降解机理还不是很清楚，但普遍认为与镍有关，即镍的迁移、镍的聚集和镍在气相中的损失。研究退化机制并提出/实施可能的解决方案是这一部分研究项目的重点。 由于锌广泛可得且价格低廉，ZIB是储存大量电力的有前途的候选者。ZIB使用高容量的锌金属阳极、金属氧化物阴极和水溶液，其能量/功率密度与锂离子电池(LIB)相似。与LIB相比，ZIB具有更高的安全性、环保性和更简单的制造条件。然而，也有一些缺点限制了可充电ZIB的实际应用。这些问题包括效率低、副产品的形成以及由于电池循环过程中与金属氧化物阴极相关的不可逆反应而导致的快速容量衰减。提高效率和稳定性的关键是合理设计新的稳定、高容量的锌离子电极材料。这项工作的重点是开发改进的锌插入阴极，以便在多个循环中实现高能量密度。

Public awareness of global climate change resulting from greenhouse gas emission has led to increasing utilization of renewable energy sources such as wind and solar, with further increases on the horizon. These sources are inherently intermittent in nature, necessitating effective methods of storing power for later use. High efficiency electrochemical energy storage (EES) devices are a key component to adopting these alternative energy sources. EES devices are the media used to store chemical energy that can be later converted back to electricity. Battery storage represents one way of providing storage, although energy could also be stored in the form of hydrogen through the electrolysis of water. EES device development and commercialization are limited by a number of materials engineering issues related to the fabrication, operation and long term reliability of these devices. The proposed research program will concentrate on the development and characterization of novel materials for EES applications, with an emphasis on two types of devices, zinc-ion batteries (ZIBs) and solid oxide electrolysis cells (SOECs). Solid oxide fuel cells (SOFCs) are devices that convert chemical energy into electrical energy. The typical fuel is hydrogen (although other fuels can be utilized) which is oxidized to water at the anode with electrons being released. An SOEC is essentially an SOFC operating in reverse. The two can be combined in a single device, referred to as a solid oxide cell (SOC). Typically, the hydrogen electrode is a cermet consisting of yttria stabilized zirconia (YSZ) and nickel (Ni). One of the issues limiting commercial application is long term stability of this electrode. The degradation mechanisms are not well understood, but are generally believed to be associated with Ni, i.e., Ni migration, Ni agglomeration and loss of Ni in the vapour phase. Studying the degradation mechanisms and proposing/implementing possible solutions is the focus of this part of the research project. ZIBs are a promising candidate to store large amounts of electricity, since zinc is widely available and inexpensive. ZIBs use a high-capacity zinc (Zn) metal anode, metal oxide cathodes and aqueous electrolytes, with energy/power densities similar to lithium-ion batteries (LIBs). ZIBs offer advantages over LIBs, including improved safety, eco-friendliness and simpler manufacturing conditions. There are, however, drawbacks that restrict practical application of rechargeable ZIBs. These include poor efficiency, the formation of byproducts and rapid capacity fading due to the irreversible reactions associated with the metal oxide cathodes during battery cycling. The key to increasing efficiency and stability is to properly design new stable and high-capacity Zn-ion electrode materials. This work focuses on developing improved Zn-insertion cathodes to enable high energy densities over many cycles.