A silicon anode is prepared for application in lithium-ion batteries that can serve different functions such as decreasing the amount of the binder and thus allowing a larger quantity of the active material, better overall integration of the electrode components upon cycling and better stability of the solid-electrolyte interface that could enable to completely get rid of the expensive electrolyte additives. The synthesis of the materials involves the functionalization of a hydrogenated silicon nanopowder by covalent attachment of polyacrylic acid that partially substitutes the silicon-oxygen bond via a silicon-carbon bond. The presence and grafting of polyacrylic acid is confirmed by transmission and scanning microscopy and energy dispersive X-ray spectroscopy, thermogravimetric analysis, Fourier transform infrared and X-ray diffraction spectroscopy. The electrochemical performance of the silicon anode is evaluated by galvanostatic cycling, cyclic voltammetry and four point-probe electronic conductivity measurements. The composite silicon anode showed a significantly improved performance, relative to the hydrogenated Si electrode in terms of gravimetric capacitance (1200 mAh g^-1 for more than 100 cycles at 0.5 C rate) with a 100 % capacity retention in a capacity limited discharge/charge cycling. When an unmodified and modified-based electrodes are allowed to fully discharge/charge, a lower initial capacity loss and a better overall physical integrity of the structure is achieved for the latter. Moreover, the composite electrode performs better at high rate discharge/charge cycles. Unlike reports making use of an electrolyte additive for silicon anode, mainly to afford stability of the solid-electrolyte interface and better cyclability, the polyacrylic acid (PAA) modified silicon composite electrode can be cycled without such additive and demonstrate a better electrochemical performance than the unmodified silicon.

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