Molten salt batteries and Ni-MH batteries

Molten salt battery

The molten salt battery is a type of battery that uses the battery’s own heating system to heat and melt the non-conductive solid salt electrolyte, so that the electrolyte becomes an ionic conductor and enters the working state. Secondary molten salt batteries generally use solid ceramics as the separator between the positive and negative electrodes and act as an electrolyte; during operation, the alkali metal or alkaline earth metal material of the negative electrode of the battery emits electrons to generate metal ions, which react with the positive electrode material through the ceramic diaphragm. At present, the secondary batteries of the molten salt battery system that have the conditions for commercial operation are mainly sodium-sulfur batteries and Zebra batteries, both of which are considered to have great potential for chemical energy storage technology and have attracted attention.

The sodium-sulfur battery is a secondary molten salt battery with metallic sodium as the negative electrode, sulfur as the positive electrode, and ceramic tube as the electrolyte diaphragm. It has the advantages of high energy density, good power characteristics, and long cycle life. There are already more than 100 application cases above the MW level worldwide. Japan is far ahead of other countries and regions in sodium-sulfur battery technology. NGK is currently the only manufacturer in the world that can provide industrialized sodium-sulfur battery products. In recent years, China has been actively carrying out research and development and industrialization of sodium-sulfur batteries. Currently, the Shanghai Institute of Ceramics, Chinese Academy of Sciences has launched prototype products for single-cell batteries.

Zebra battery is a secondary molten salt battery with metallic sodium as the negative electrode, nickel chloride as the positive electrode, and ceramic tube as the electrolyte separator. With the characteristics of high energy density, high specific power, fast charge and discharge, and good safety performance, it has long been regarded as one of the more ideal automotive power batteries. At present, Zebra batteries of various sizes ranging from 20 to 120 kWh have been developed for various models. In addition, Zebra batteries also have application prospects in ships. At present, Zebra battery technology in the world is mainly controlled by two companies, FZSonick in Switzerland and GE in the United States. China and Japan have hardly conducted research on Zebra batteries.

NiMH batteries

Ni-MH batteries are developed on the basis of high-voltage nickel-hydrogen batteries used in aerospace. Like traditional nickel batteries, they are composed of hydrogen ions and metallic nickel. The power reserve is 30% more than nickel-cadmium batteries and lighter than nickel-cadmium batteries. The service life is longer and it is more environmentally friendly.

Japan’s Sanyo Battery Company first began mass production of nickel-hydrogen batteries in October 1990. After more than 20 years of development, the current application areas are mainly small electronic devices and hybrid vehicles. In the field of static energy storage, although traditional nickel-hydrogen batteries have cost advantages, they are at a disadvantage in terms of charge-discharge rate performance and volumetric energy density, as well as poor power performance. Therefore, there are fewer successful commercial cases of nickel-hydrogen batteries in this field.

In order to prevent Panasonic from becoming a company with an absolute dominant position in the global automotive nickel-hydrogen battery market after the acquisition of Sanyo Electric Co., Ltd. At the request of the Ministry of Commerce of China, in January 2011, China Corun Corporation acquired the Shonan battery factory of Panasonic Corporation of Japan, thus becoming an important manufacturer in the field of nickel-hydrogen batteries. In addition, major manufacturers include Ovonic of the United States, Cobasys of the United States, Saft of France, Toyota, Honda, Ford, Japan’s Kawasaki Heavy Industries Co., Ltd., and China Chunlan Group.