Boron-Doped Spherical Hollow-Porous Silicon Local Lattice Expansion toward a High-Performance Lithium-Ion-Battery Anode

Abstract

Silicon (Si) attracts extensive attention as the advanced anode material for lithium (Li)-ion batteries (LIBs) because of its ultrahigh Li storage capacity and suitable voltage plateau. Hollow porous structure and dopant-induced lattice expansion can enhance the cycling stability and transporting kinetics of Li ions. However, it is still difficult to synthesize the Si anode possessing these structures simultaneously by a facile method. Herein, the lightly boron (B)-doped spherical hollow-porous Si (B-HPSi) anode material for LIBs is synthesized by a facile magnesiothermic reduction from B-doped silica. B-HPSi exhibits local lattice expansion located on boundaries of refined subgrains. B atoms in Si contribute to the increase of the conductivity and the expansion of lattices. On the basis of the first-principles calculations, the B dopants induce the conductivity increase and local lattice expansion. As a result, B-HPSi electrodes exhibit a high specific capacity of ∼1500 mAh g–1 at 0.84 A g–1 and maintains 93% after 150 cycles. The reversible capacities of ∼1250, ∼1000, and ∼800 mAh g–1 can be delivered at 2.1, 4.2, and 8.4 A g–1, respectively.

Silicon Anodes for High‐Performance Storage Devices: Structural Design, Material Compounding, Advances in Electrolytes and Binders

“…Moreover, the larger pores can also help in promoting better SEI formation and overall structure preservation . The interconnected porous structure also promotes the efficient transport of electrons and lithium ions . The methods for preparing porous silicon mainly include magnesiothermic reduction and acid/alkali etching.…”

Function and Application of Defect Chemistry in High‐Capacity Electrode Materials for Li‐Based Batteries

“…The latter Si subgrains are dedicated to the high cycling stability by alleviating the volume change. [101] Unlike B doping (p-type) with higher insertion potential, the P-doped Si has lower Li insertion potential, indicating the smaller thermodynamic driving force for lithiation. [106][107] Sakaguchi et al have investigated the effect of P dopant on reactive behavior and the electrochemical performance of Si electrodes.…”

“…[117] Furthermore, O vacancies can promote phase transition at the electrode/electrolyte interface by the modification of surface thermodynamics and avoid the structural disintegration on the electrode surface. [118] For instance, intrinsic structural instabilities of MnO with wurtzite Reproduced with permission from Ref., [101] Copyright 2019, American Chemical Society. (b) Schematic diagram and long cycling performance (when coated with carbon and graphene oxide) of porous Si from Fe and B defect etching.…”

Interface Heteroatom‐doping: Emerging Solutions to Silicon‐based Anodes

“…Boron (1s 2 2s 2 2p 1 ), as a graphitization catalyst, can significantly enhance the graphitization of carbon . Boron doping could modify the electronic properties of the graphitic framework, which is beneficial for lithium ion transport behavior . It has been widely confirmed that boron doping can improve the specific capacity and coulombic efficiency of Si‐based composite anode.…”