PROGRESS ARTICLE NATURE MATERIALS DOI:10.1038/NMAT4170 This method is relatively cheap and has the.Y. datory prope elect Vei,D.et phene and he 15 K.R.et al.S ing 16. ith 1 vents t the commercial stage.However 18. eri 19. through gr 20. priate wof the funding and hum 22 anotubes to form -distant ortant esults 58872876 body of tinu e the ben 24 Moore,R.B.&Graphene-based rics Phr Chem Chon.Pls 13.15384-15402 (201) atrix.which buffer event and the lat 42.2929-293720 ide hi onfirmed a the verthel ite.the 28 (-basdcom materials.Nature g is achie compounds will 29 ects and future. 5195.2 ure Vinning the stent investment nt from 3(1995 stry and res arch-funding inst ution 31. Liu,Y.Xue R.Me 32 tion of graphene in eesds epted 7 No mber 2014:published 4 of alloy anodes fo References 35 aelle,R.P.Carbo 18- 36 37 ent and future -o cels Aca 130,51-5(24) 38 107-13120120 nergy ste ,3480- 40. emical energy storage 9 42.Hu 0 04 10. 43. 4 Les.W or lithiu NATURE MATERIALS ADVANCE ONLINE PUBLICATION www.nature.com/naturemateriab 2014 Macmillan Publishers Limited All rights reserved 8 NATURE MATERIALS | ADVANCE ONLINE PUBLICATION | www.nature.com/naturematerials of GO to RGO. This method is relatively cheap and has the potential for scalability — mandatory properties for widespread adoption — but introduces both intrinsic and extrinsic defects, which strongly affect electrochemical properties. Although for some applications the defects function as catalyst sites to improve cell kinetics (for example, in lithium–air and sodium–air batteries), in other cases they strongly reduce the performance. For example, RGO cannot compete with the widespread carbonaceous materials commonly employed in commercial LIBs. In fact, despite their very promis￾ing initial performance, RGO electrodes show a limited cycle life98 compared with well-established graphite electrodes. With respect to EDLCs, the limited cycle life and low density of RGO-based elec￾trodes prevents their transition to the commercial stage. However, some strategies for improving the packing density of graphene￾based materials have been proposed. Nevertheless, the macroporous nature of graphene, in general, seriously affects its volumetric energy density. In this case, the common practice of evaluating EDLC per￾formance through gravimetric data might lead to misleading con￾clusions. Because low-density and few-micrometre-thick electrodes are often reported, volumetric data are surely more appropriate63. In view of the funding and human resources devoted world￾wide to this unique material, we may expect to see a turnover in the not-too-distant future. Some important results support this vision. In fact, a growing body of research into graphene-based full LIBs37,38,99,100 is continuing to prove the benefits of graphene for this important application. In addition, it has been demonstrated that graphene (or RGO) may find its true role when employed in com￾posite electrodes. Here, graphene layers and electroactive particles work symbiotically, with the former providing a stiff and conduc￾tive matrix, which can buffer eventual volume changes, and the lat￾ter helping to avoid layer re-stacking. Graphene-based composites have, in fact, shown outstanding performance in LIBs44–46, SIBs51–55, pseudocapacitors58,59,62,66 and LSB81–83. Moreover, a few preliminary studies into full SIBs51,55 have confirmed graphene exploitation in the ‘beyond lithium’ battery generation. 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Novel synthesis of high performance anode materials for lithium-ion batteries (LIBs). J. Mater. Chem. A 2, 1589-1626 (2014). PROGRESS ARTICLE NATURE MATERIALS DOI: 10.1038/NMAT4170 © 2014 Macmillan Publishers Limited. All rights reserved