1000 Wh L-1 lithium-ion batteries enabled by crosslink-shrunk tough carbon encapsulated silicon microparticle anodes

Fanqi Chen; Junwei Han; Debin Kong; Yifei Yuan; Jing Xiao; Shichao Wu; Dai-Ming Tang; Yaqian Deng; Wei Lv; Jun Lu; Feiyu Kang; Quan-Hong Yang

doi:10.1093/nsr/nwab012

1000 Wh L^-1 lithium-ion batteries enabled by crosslink-shrunk tough carbon encapsulated silicon microparticle anodes

Natl Sci Rev. 2021 Jan 23;8(9):nwab012. doi: 10.1093/nsr/nwab012. eCollection 2021 Sep.

Authors

Fanqi Chen¹, Junwei Han², Debin Kong³, Yifei Yuan⁴, Jing Xiao¹, Shichao Wu¹, Dai-Ming Tang⁵, Yaqian Deng², Wei Lv², Jun Lu⁴, Feiyu Kang², Quan-Hong Yang¹

Affiliations

¹ Nanoyang Group, State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
² Shenzhen Geim Graphene Center, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
³ CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China.
⁴ Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, USA.
⁵ International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba 305-0044, Japan.

Abstract

Microparticulate silicon (Si), normally shelled with carbons, features higher tap density and less interfacial side reactions compared to its nanosized counterpart, showing great potential to be applied as high-energy lithium-ion battery anodes. However, localized high stress generated during fabrication and particularly, under operating, could induce cracking of carbon shells and release pulverized nanoparticles, significantly deteriorating its electrochemical performance. Here we design a strong yet ductile carbon cage from an easily processing capillary shrinkage of graphene hydrogel followed by precise tailoring of inner voids. Such a structure, analog to the stable structure of plant cells, presents 'imperfection-tolerance' to volume variation of irregular Si microparticles, maintaining the electrode integrity over 1000 cycles with Coulombic efficiency over 99.5%. This design enables the use of a dense and thick (3 mAh cm^-2) microparticulate Si anode with an ultra-high volumetric energy density of 1048 Wh L^-1 achieved at pouch full-cell level coupled with a LiNi_0.8Co_0.1Mn_0.1O₂ cathode.

Keywords: anode; lithium-ion batteries; mechanical stability; silicon microparticles; volumetric capacity.