Recently, Peng Huisheng/Wang Bingjie team from the Institute of Fiber Electronic Materials and Devices, the Department of Polymer Science, the Advanced Materials Laboratory, and the State Key Laboratory of Polymer Molecular Engineering of Fudan University, together with Wang Yonggang, Zhou Haoshen, Lu Jun, and other co authors, developed a new type of calcium oxygen gas battery, which can conduct electrochemical charge and discharge at room temperature and operate stably for 700 cycles, Showcasing advantages such as high security and low cost. Recently, the relevant results were published online in the journal Nature under the title of "Room Temperature Rechargeable Calcium Oxygen Batteries". Calcium metal has the characteristics of low redox potential and multivalence. Combined with China's abundant calcium resources, battery systems based on metal calcium have broad prospects in future energy applications. Among them, calcium oxygen batteries have the highest theoretical energy density, but have not been able to achieve stable charging and discharging at room temperature before. In the past, the development of calcium oxygen batteries was severely restricted due to the difficulty in finding an electrolyte that could match the calcium metal negative electrode and adapt to high electrode potential air positive electrodes. To solve this problem, the team successfully prepared a new type of electrolyte based on dimethyl sulfoxide/ionic liquid by systematically designing solvents, electrolyte salts, and electrolyte ratios. This effectively met the high requirements of the positive and negative electrodes of the battery, and developed a new type of calcium oxygen battery that can work at room temperature. It is understood that the calcium oxygen battery is mainly composed of three parts: a metal calcium negative electrode, a carbon nanotube air positive electrode, and an organic electrolyte. The design of this battery not only optimizes performance and cost, but also takes into account environmental sustainability and application requirements in flexible electronic devices. Among them, the metal calcium negative electrode not only has lower cost, but also has higher theoretical capacity, which is conducive to achieving higher energy density in the entire battery. (Lai Xin She)