Bismuth Nanoparticle@Carbon Composite Anodes for Ultralong Cycle Life and High‐Rate Sodium‐Ion Batteries

Abstract

Bismuth has emerged as a promising anode material for sodium‐ion batteries (SIBs), owing to its high capacity and suitable operating potential. However, large volume changes during alloying/dealloying processes lead to poor cycling performance. Herein, bismuth nanoparticle@carbon (Bi@C) composite is prepared via a facile annealing method using a commercial coordination compound precursor of bismuth citrate. The composite has a uniform structure with Bi nanoparticles embedded within a carbon framework. The nanosized structure ensures a fast kinetics and efficient alleviation of stress/strain caused by the volume change, and the resilient and conductive carbon matrix provides an interconnected electron transportation pathway. The Bi@C composite delivers outstanding sodium‐storage performance with an ultralong cycle life of 30 000 cycles at a high current density of 8 A g−1 and an excellent rate capability of 71% capacity retention at an ultrahigh current rate of 60 A g−1. Even at a high mass loading of 11.5 mg cm−2, a stable reversible capacity of 280 mA h g−1 can be obtained after 200 cycles. More importantly, full SIBs by pairing with a Na3V2(PO4)3 cathode demonstrates superior performance. Combining the facile synthesis and the commercial precursor, the exceptional performance makes the Bi@C composite very promising for practical large‐scale applications.

Ionic‐Conducting and Robust Multilayered Solid Electrolyte Interphases for Greatly Improved Rate and Cycling Capabilities of Sodium Ion Full Cells

“…As shown in Figure 1d, the rate capability of our Bi/C composite, in the DME‐based electrolyte, was comparable to those of state‐of‐art bismuth‐based anodes. [ 9,11,19,26,36–38 ] Importantly, the rate capabilities of the bismuth‐based anodes, in an ether‐based electrolyte, were much better than those in an ester‐based electrolyte. Considering the higher ionic conductivity (0.95 mS cm −1 ) of the EC/DEC‐based electrolyte than that (0.82 mS cm −1 ) of the DME‐based electrolyte (Figure S6a, Supporting Information), [ 39 ] the high rate and reversible capacities could be attributed to the highly ionic conductive SEI formed in DME‐based electrolyte.…”

“…[ 13–21 ] The enhanced performance of bulk bismuth in an ether‐based electrolyte was first reported by Chen’s group; [ 19 ] the microsized bulk bismuth could be incorporated into a porous architecture during the cycling, which ensures continuous sodium‐ion transport and structural stability for over 2000 cycles. Motivated by an intriguing phenomenon where the SEI itself was associated with the cyclic stability, the sodium storage performances could be further enhanced by matching ether‐based electrolytes with bismuth‐based composite materials, such as Bi@C, [ 22 ] Bi/N‐C, [ 23 ] Bi/graphite, [ 24 ] and Bi/graphene. [ 25,26 ] Consequently, both the long‐term stability for >10 000 cycles and ultra‐high rate capabilities at 300 C could be achieved.…”

High power Na3V2(PO4)3 symmetric full cell for sodium-ion batteries

“…Other complex electrode modication strategies attempting to address NVP's low electronic conductivity have resulted in comparatively low electrochemical performance. [16][17][18] A recent NVP-based full cell in an asymmetric conguration with Bi and Sn anodes showed high reversible capacity in a DEGDME-based electrolyte; [19][20][21] however, its rate and cycling performances were not adequate. In contrast, our group recently reported the excellent rate performance and long-term cycling performance of an NVP cathode in a dimethoxyethane (DME) electrolyte.…”

PAANa-induced ductile SEI of bare micro-sized FeS enables high sodium-ion storage performance

“…Various types of materials [19][20][21][22][23], such as hard carbon [19], alloy-based materials [24,25], organic compounds [26,27], and metal sulfides [28], have been widely investigated as anodes for SIBs. Hard carbon is one of the promising anode materials for commercial production because of its cost effectiveness and simple processing technology.…”