Large areal capacity all-in-one lithium-ion battery based on boron-doped silicon/carbon hybrid anode material and cellulose framework

Si, featuring ultra-large theoretical specific capacity, is a very promising alternative to graphite for Li-ion batteries (LIBs). However, Si suffers from intrinsic low electrical conductivity and structural instability upon lithiation, thereby severely deteriorating its electrochemical performance. To address these issues, B-doping into Si, N-doped carbon coating layer, and carbon nanotube conductive network are combined in this work. The obtained Si/C hybrid anode material can be grown onto the Cu foil without using any binder and delivers large specific capacity (2328 mAh g-1 at 0.2 A g-1), great rate capability (1296.8 mAh g-1 at 4 A g-1), and good cyclability (76.7% capacity retention over 500 cycles). Besides, a cellulose separator derived from cotton is found to be superior to traditional polypropylene separator. By using cellulose as both the separator host and the mechanical skeleton of two electrodes, a flexible allin-one paper-like LIB is assembled via a facile layer-by-layer filtration method. In this all-in-one LIB, all the components are integrated together with robust interfaces. This LIB is able to offer commerciallevel areal capacity of 3.47 mAh cm-2 (corresponding to 12.73 mWh cm-2 and 318.3 mWh cm-3) and good cycling stability even under bending. This study offers a new route for optimizing Si-based anode materials and constructing flexible energy storage devices with a large areal capacity. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

B-doping into Si, combined with N-doped carbon coating and carbon nanotube conductive network, addresses the low electrical conductivity and structural instability issues of Si in Li-ion batteries (LIBs). Additionally, a cellulose separator derived from cotton is used to assemble a flexible all-in-one LIB with high areal capacity and good cycling stability.