## 1 Introduction  
Under the current global development situation, energy security and environmental protection are facing multiple complex problems and challenges, such as increasing risks in the energy supply chain and intensified climate change [1; 2; 3; 4; 5; 6]. These issues are not only related to national economic development and social stability, but also directly affect the sustainability of the global ecological environment and the quality of human survival [7; 8; 9]. People all over the world have gradually realized their severity and begin to seek effective methods to balance them, so green and low-carbon new energy technologies and industries have gained attention and rapidly developed [10; 11]. In this context, underground storage has attracted widespread concern. This refers to facilities that utilize underground space for storage, and currently there are four main types of depleted oil and gas reservoir, aquifer, salt cavern, and abandoned mine. With the growth of new energy demand, underground storage not only plays an important role in ensuring the stable supply and safe reserve of conventional energy (such as natural gas, oil, etc. ), but also undertakes the important mission of energy transformation and the development of new energy (compressed air energy storage (CAES), hydrogen energy, CCES, etc.) and environmental improvement [12; 13; 14; 15; 16]. Salt rock is found to have especial characteristics such as good creep behavior, low permeability, and good damage recovery, and is thus recognized as an ideal medium for energy underground storage. The salt cavern, formed by mining in salt rock formations, has become the first choice for the underground storage of energy resources such as natural gas, petroleum, compressed air, hydrogen, helium, etc. [17; 18; 19; 20]. The use of underground salt caverns for energy storage can be traced back to the 1950s. North America and Europe were the first to explore the application of salt caverns for gas storage, and, by 2009, 74 underground salt cavern gas storage facilities had been built [21]. In the 1970s, after the outbreak of the oil crisis, strategic oil reserves received great attention. The United States successively used underground salt rocks in the Gulf of Mexico to build some national oil reserves with a storage capacity of 720 million barrels. Germany, Russia, Canada, etc., have also successively used salt caverns to complete the construction of crude oil reserves [22]. The exploration of CAES in salt caverns began in the 1980s. Germany first built a 290,000 kW salt cavern CAES power station in Huntorf in 1978, and the United States built the world's second commercial salt cavern CAES power station in McIntosh, Alabama, in 1991 [23]. As for hydrogen and helium storage, the United Kingdom, the United States, and Germany have all built demonstration salt cavern hydrogen storage, and Russia has built the world's first salt cavern helium storage. China began exploring underground energy storage in the 1990s. After more than 20 years of practical experience, the first salt cavern gas storage in China and even in Asia--the Jintan gas storage in Jiangsu province--was built in 2007, which has also initiated the plan and construction of several underground salt cavern gas storage facilities in the cities of Chuzhou, Huai'an, Pingdingshan, Yexian, Yunying, and so on. In May 2022, a salt cavern CAES demonstration power station with a power generation scale of 60 MW was successfully completed and put into operation in Jintan, Jiangsu province, marking a qualitative leap in China's CAES technology from theoretical experiments to engineering applications. This project also opens a grand blueprint for the construction of salt cavern CAES facilities in China. Several large-scale salt cavern CAES power station projects have been planned and deployed in cities such as Yunying,Feicheng, Heze, Huai'an, etc. [24; 25]. Additionally, salt cavern oil storage, helium storage, and hydrogen storage are also being planned and constructed in full swing.