New Formulations of High-Voltage Cathodes for Li-Ion Batteries with Water-Processable Binders

摘要

The use of water-processable binders could lower production costs and grant easier and more environment-friendly production of Li-ion batteries. This work investigates the use of two water-processable binders, namely polyvinylacetate (PVA) and sodium alginate (Alg), in high-voltage cathode electrodes for Li-ion batteries. We focused our work on the use of these sustainable binders for cathodes based on LiNi_(0.5)Mn_(1.5)O_4, a commercially available material with a very high Li~+ deinsertion/insertion potential (4.7-4.75 V versus Li~+/Li) and a theoretical specific capacity of 147 mAh g~(-1). The electrochemical performance of cathodes with PVA and Alg are compared to that of PVdF-based electrodes at 30°C in conventional electrolyte. Among all, Alg-based cathodes show the best rate capability up to 5C and cycle stability, with 95% capacity retention after 100 cycles because of the formation of a thinner and less resistive layer on the electrode than PVA- or PVdF-based cathodes.