ИСТИНА

Today, lithium-ion batteries are widely used. However, they have a number of disadvantages, including high manufacturing costs and high environmental impact. The development of water-soluble polymer binders for battery electrodes can serve as one of the ways to eliminate these shortcomings, since they make it possible to obtain electrodes without the use of organic solvents [1]. In this work, positive electrodes for lithium-ion batteries based on LiFePO4 were obtained; singlewalled carbon nanotubes were used as a conductive component; water-soluble hydrolyzed polyacrylonitrile and carboxymethylcellulose were used as a binders. To achieve good capacity and cycling performance, it is important to obtain stable dispersions of the conductive component in the electrode suspension. It was found that stable dispersions with carbon nanotubes in an aqueous solution of hydrolyzed polyacrylonitrile are formed at pH≈5. In the case of carboxymethylcellulose, dispersions are formed in a wide pH interval. The properties of the resulting electrode are significantly influenced by the acid used to reduce the acidity of the initial solution of the polymer binder. LiFePO4 particles and the current collector are more stable in the presence of CH3COOH and H3PO4 than in HCl, which makes it possible to achieve high values of specific capacity. The effect of the separator on the cycling performance of the electrode was also investigated. As a result, specific cathode capacitance of 160 mAh g−1 was achieved, which is close to the theoretical value for LiFePO4 of 170 mAh g−1 . It was found that the electrodes prepared from polymer solutions with fully dispersed carbon nanotubes had a larger capacity at high current densities and a more uniform distribution of carbon nanotubes in the composite [2]. The use of a separator that prevents the growth of lithium dendrites had a positive effect on the stability of the battery capacity, so the loss of capacity over 100 charge-discharge cycles was less than 2%. References [1] Energy & Environmental Science 2018, 11, 3096 [2] ACS Applied Energy Materials 2021, 4, 12310 Acknowledgements This work was supported by the Russian Science Foundation (project No 24-13-00107)