Si/SiO_x‐Conductive Polymer Core‐Shell Nanospheres with an Improved Conducting Path Preservation for Lithium‐Ion Battery

Abstract

Non-stoichiometric SiO based materials have gained much attention as high capacity lithium storage materials. However, their anode performance of these materials should be further improved for their commercial success. A conductive polymer, poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS), is employed as a flexible electrical interconnector to improve the electrochemical performance of Si/SiO nanosphere anode materials for lithium ion batteries (LIBs). The resulting Si/SiO -PEDOT:PSS core-shell structured material with the small amount (1 wt %) of PEDOT:PSS shows the improved initial reversible capacity of 968.2 mA h g with excellent long-term cycle performance over 200 cycles. These promising properties can be attributed to the use of the electroconductive and flexible PEDOT:PSS shell layer, which protects the electrical conduction pathways in the electrode from the large volume changes of silicon during cycling.

Multiscale Engineered Si/SiOx Nanocomposite Electrodes for Lithium-Ion Batteries Using Layer-by-Layer Spray Deposition

“…6 SiOx based anode materials show a smaller and potentially easier to accommodate volume change of up to 160% upon Li insertion, and a corresponding lower theoretical capacity of 3172 mAh g -1 . [7][8][9][10][11][12][13][14] To address the shortcomings of Si as an anode, a wide range of Si and/or SiOx nanomaterial design concepts have been developed, including one-dimensional Si nanowires, 15 hollow nanoparticles, 16 nanotubes, 17 Si-C nanocomposites, [18][19] double-walled Si-SiO2 hollow tubes 20 and Si-C "pomegranate" structures. 21 Common to all the nano-scale approaches is the idea that strain in such nanostructures can be relaxed without mechanical fracture because induced defects, such as dislocations, can readily run out to the free surface so that significant plastic deformation and macro-scale failure are avoided.…”

Silicon-Based Anode with High Capacity and Performance Produced by Magnesiothermic Coreduction of Silicon Dioxide and Hexachlorobenzene

“…It is worth mentioning that stoichiometric SiO x based materials can also effectively alleviate the volume Si volume changes during alloying/dealloying with Li + [18]. In this regard, Min-Sik Park and his group have done a lot of work [19][20][21][22]. Eunjun Park et al prepared a dual-size Si nanocrystal-embedded SiO x nanocomposite via costeffective sol-gel reaction of triethoxysilane with commercially available Si nanoparticles as a highcapacity Li + storage material and the nanocomposite provided a high capacity (1914 mA h/g) with a notably improved initial efficiency (73.6%) and stable cycle performance over 100 cycles [19]; he also used a conductive polymer, poly (3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) as a flexible electrical interconnector to improve the electrochemical performance of Si/SiO x nanosphere anode materials for lithium ion batteries (LIBs) and the resulting Si/SiO x -PEDOT:PSS core-shell structured material with the small amount (1 wt %) of PEDOT:PSS showed the improved initial reversible capacity of 968.2 mA h/g with excellent long-term cycle performance over 200 cycles [20].…”

Tailoring the oxygen content in lithiated silicon oxide for lithium‐ion batteries

“…[13][14][15][16][17][18] To solve this problem, researchers have developed structurally modified Si, such as nanostructures, [19][20][21] core-shell structures with carbonaceous material to form silicon/carbon composites, 9,[22][23][24] and alloyed silicon with active/inactive elements. [25][26][27][28] Silicon oxide, SiO x (x ≤ 2), has also been considered as an alternative LIB anode because of its more stable cycling performance than that of the pristine silicon anode. 29,30 It is well-known that solid SiO x is thermodynamically unstable at all temperatures; amorphous Si and SiO 2 clusters in SiO x lead to an active/inactive composite (disproportionation reaction) that facilitates buffering the strain during cycling, resulting in substantially improved reversible capacities.…”

“…This causes the pulverizing of Si particle, resulting in loss of electrical contact, and thus leading to early capacity fading 13‐18 . To solve this problem, researchers have developed structurally modified Si, such as nanostructures, 19‐21 core‐shell structures with carbonaceous material to form silicon/carbon composites, 9,22‐24 and alloyed silicon with active/inactive elements 25‐28 …”