Tetrafluoroboric acid diethyl ether complex is widely used in organic synthesis as a catalyst or reagent. It is particularly effective in promoting various chemical reactions, including polymerization, alkylation, and cyclization processes. In the production of pharmaceuticals, it serves as a key intermediate in the synthesis of active pharmaceutical ingredients (APIs). Additionally, it is employed in the preparation of boron-containing compounds, which are essential in materials science and electronics. Its ability to stabilize reactive intermediates makes it valuable in the development of advanced materials and coatings. In electrochemistry, it is utilized as an electrolyte additive to enhance the performance of batteries and other energy storage devices.