Explain the performance characteristics of potassium ion batteries

Ignore the potassium ion battery? In order to obtain the highest energy density, the metal lithium in the upper left corner of the periodic table becomes the first choice for secondary batteries. Its extremely negative standard electrode potential (-3.04v) means that the battery has a high voltage output after being in contact with the positive electrode group. Lithium is the lightest metal, which means it has a higher gram capacity. Energy u003d specific capacity × voltage, so the energy density of lithium batteries is almost the highest among current batteries. Lithium batteries also have the advantage of being small. Therefore, the industrialization of the 1990s rapidly changed the categories of smartphones, cameras, laptops, and electric vehicles. However, the development of lithium batteries seems to have encountered bottlenecks. Energy density has risen slowly, costs have fallen slowly, fast charging, the habit of temperature planning, larger planning layouts (electric vehicles, energy storage), and resource abundance are facing challenges. So people have been looking for a new secondary battery technology to make up for the deficiencies of lithium and sodium, and a large amount of rechargeable magnesium, zinc, and aluminum are now important research directions. High price, however, the research of magnesium, zinc, and aluminum ion secondary batteries is very difficult. Its high price and radius is smaller than that of lithium. It is tightly adsorbed with anions and is difficult to embed and crystal structure at home, and its powerful dissolution effect The electrolyte ion channel is also difficult to desolvate during the embedding process, so it is very slow. Nearly 1,000 times the reserves of sodium and lithium, lithium battery technology and information systems that can be used for reference in the vicinity of nature reserves and the development of lithium will supply the most battery systems. The development of relevant engineering pilots at home and abroad has made some progress. In particular, the fixed storage category may provide a powerful solution (the energy density is slightly lower than that of lithium batteries). Sodium ions and potassium ions are related to the higher abundance of lithium ions. However, in the case of sodium ion batteries that have received more attention in the academic community, potassium ion batteries, one of the alkaline brothers, have received much less attention. Although as an important group of elements similar to sodium and potassium, there are similar reserves, but between sodium and potassium, the former seems to be more promising. Whether sodium lithium ion and ion radius are closer (potassium ion radius and mass are larger), more importantly It is hoped that many information systems will directly affect the development of lithium batteries. If the low-cost industrialization of sodium-ion batteries is not far away, but in the case of the same data structure and energy density, it is almost unnecessary to make potassium-ion batteries ( But in practice, there is no need to set it in this case, which will be explained later). However, recent experiments on sodium ion batteries and potassium ion batteries indicate that the impact of potassium ions may be compensated by some of its unique advantages. (1) Redox potential. As an element of the first main group, the potential of the three electrodes does not conform to our general guess, instead of getting negative from top to bottom (that is, simply losing electrons). Lithium -3.04V. Sodium -2.71V. K-2.93V Because the voltage of the battery is equal to the potential difference between the positive and negative electrodes, the sodium composition data of the sodium ion battery and the negative electrode potential are not so negative and often have a low voltage, while the potentials of lithium and potassium are more similar. Therefore, in terms of high voltage, potassium ion batteries are expected to have the same advantages as lithium batteries. (2) Embedding of graphite cathode. As the top cathode material of lithium batteries, graphite should be copied to the cathode of sodium and potassium ion batteries, but the test results show that sodium ions cannot be embedded in the graphite layer. Nowadays, hard carbon is an important development direction for sodium ion battery cathode materials, but its function It is not very satisfactory, and the price is higher than that of graphite. Surprisingly, potassium ions with a larger radius can be embedded in graphite, providing a specific capacity of about 250 mAh/g [1,2]. Lithium and potassium are more similar. The charge-discharge curve of alkali metal ions in graphite is different from that of hard carbon graphite anodes. (a) Lithium ion and copper ion collection solution; (b) Sodium ion and aluminum collection solution; (c) Potassium ion and copper collection solution; (d) Potassium ion and aluminum collection. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous post: Analysis of the advantages and disadvantages of lithium batteries