In Situ Thermally Cross‐linked Polyacrylonitrile as Binder for High‐Performance Silicon as Lithium Ion Battery Anode

Abstract

Electrode integrity and electric contact between particles and between particle and current collector are critical for electrochemical performance, especially for that of electrode materials with large volume change during cycling and with poor electric conductivity. We report on the in situ thermally cross-linked polyacrylonitrile (PAN) as a binder for silicon-based anodes of lithium-ion batteries. The electrode delivers excellent cycle life and rate capability with a reversible capacity of about 1450 mA h g(-1) even after 100 cycles. The improved electrochemical performance of such silicon electrodes is attributed to heat-treatment-induced cross-linking and the formation of conjugated PAN. These findings open new avenues to explore other polymers for both anode and cathode electrodes of rechargeable batteries.

Lithium Storage in Heat‐Treated SnF2/Polyacrylonitrile Anode

“…The component at 400.4 eV belongs to pyrrolic N, which indicates breakage of the CN bond and reconfiguration of the pyrrole ring and pyridine ring in the cyclization process. These results agree well with our previous work 16. Heat treatment above 200 °C results in the breaking down of nitrile groups (CN), formation of a conjugated system (CNCN), and cross‐linking of PAN.…”

“…The peaks at about 1450 and about 3000 cm −1 are assigned to the CH stretching vibration of PAN, and the peak at 2243 cm −1 is due to stretching of its CN group. The OH band at 1633 cm −1 and the CO band at 1735 cm −1 of methyl acrylate (impurity) in commercial PAN16 disappears after heating at 230 °C. In addition, two new peaks are observed at 1582 and 1612 cm −1 for CN (or CC) and amide groups, respectively.…”

“…Recent studies15 indicate that cross‐linked PAN with a conjugated structure exhibits outstanding mechanical strength and good electrical conductivity. Shen et al 16. then reported that thermal treatment can lead to cross‐linking of the PAN chains and improve the cycling performance of the Si electrode.…”

The progress of novel binder as a non-ignorable part to improve the performance of Si-based anodes for Li-ion batteries

“…However, many problems hinder the performances and the commercial application of Si-based anodes, such as safety issues, capacity fading, rate capability, electrode swelling 6 and cycle life. 8,9 To overcome these drawbacks, most of attentions have been intensively paid on active materials. 8,9 To overcome these drawbacks, most of attentions have been intensively paid on active materials.…”

Improve the Overall Performances of Lithium Ion Batteries by a Facile Method of Modifying the Surface of Cu Current Collector with Carbon

“…[7][8][9][10][11] For example, Guo 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 3 and collaborators had demonstrated that the electrochemical properties of LIBs could be significantly enhanced by constructing electronically conducting nanocarbon networks in the electrode materials. [12] However, LIBs are integrated systems, and hence their electrochemical performances are finally determined by not only electrode materials but also other components and factors, such as the structure of the whole electrodes, current collectors, [13,14] binder, [15,16] separator, and so on.…”