Supplementary Information

Polyvinyl alcohol grafted poly (acrylic acid) as

water-soluble binder with enhanced adhesion

capability and electrochemical performances

for Si anode

Jiarong He a, b, Lingzhi Zhang a, *

a Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable

Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese

Academy of Sciences, No.2 Nengyuan Rd., Guangzhou, Guangdong 510640, China

b University of Chinese Academy of Sciences, Beijing 100049, China

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* Corresponding author

E-mail address: lzzhang@ms.giec.ac.cn (L.Z. Zhang)

Tel.: +86-20-37246025; Fax: +86-20-37246026.

Fig. S1. The solubility differences between PVA and PVA-g-PAA in ethanol (a), and

between PAA and PVA-g-PAA in acetone (b).

Fig. S2. TEM image of pristine Si particle (a) and its corresponding SiO2 layer on the surface

(b), low magnification TEM image of individual Si particle (c), the elemental composition (d)

and its corresponding EDS mapping images (e and f) of Si (yellow) and O (green) element.

Fig. S3. 1H NMR spectra of PVA (a) and PVA-g-10PAA (b) (D2O, 400 MHz, 298 K).

Fig. S4. The swelling tests of PVA, PVA-g-2.5PAA, PVA-g-5PAA, PVA-g-10PAA, PVA-g-

15PAA, PAA and CMC binder films in the electrolyte of EC/DEC/DMC (v/v/v=1/1/1) at

room temperature.

Fig. S5. CV curves of Si electrode with different binders at a scan rate of 0.2 mV s -1 for the

first 5 cycles: (a) PVA, (b) PVA-g-10PAA, (c) PAA and (d) CMC.