19042
The functionalized Si encapsulated by graphene sample exhibits a capacity of 2250 mAh g ( - 1 ) ( based on the total mass of graphene and Si ) at 0 . 1C and 1000 mAh g ( - 1 ) at 10C , and retains 85 % of its initial capacity even after 120 charge / discharge cycles .
 Si, graphene, graphene, Si
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Si, graphene, graphene, Si