Robust graphene oxide‐coated porous biochar skeleton constructed on SnO ₂ nanoparticles as high‐performance composite anode for lithium‐ion batteries

Abstract SnO 2 is regarded as a promising lithium storage material due to the advantage of sequential conversion‐alloying reaction mechanism. Unfortunately, large volume expansion and undesirable reaction reversibility are identified as two fatal drawbacks. Herein, SnO 2 nanoparticles encapsulated in graphene oxide‐coated porous biochar skeleton (SnO 2 /PB@GO) are skillfully constructed via an efficient one‐step hydrothermal process to be employed as composite anode materials, in which the PB skeleton extracted from waste tea‐seed shells possesses enough space to buffer drastic volume variation and the GO coating acts as robust physical matrix to prevent structural degradation. Moreover, double‐carbon components successfully anchor SnO 2 nanoparticles to promote contact and reaction between Sn and Li 2 O to guarantee high reaction reversibility and structural integration of SnO 2 /PB@GO electrode. As expected, SnO 2 /PB@GO‐based cell achieves high reversible specific capacity of 783.5 mAh·g −1 after 100 cycles at 0.1 A·g −1 and delivers desirable cycling stability with capacity retention ratio of 81.62% after 300 cycles at 1.0 A·g −1 . Therefore, this work may provide new perspectives on the modification of conversion or alloying type anodes for lithium‐ion batteries and present a feasible strategy to take full advantage of the waste biomass.