Stable Sodium Storage of Red Phosphorus Anode Enabled by a Dual-Protection Strategy

Abstract

Red phosphorus is appealing for anode use in sodium-ion batteries. However, the synthesis of electrochemically stable red P anodes remains challenging due to a notable volume variation upon (de)sodiation, and limited synthetic methods arising from the low ignition and sublimation temperatures. To address the above problems, we herein successfully develop an industrially adaptable process for scalable synthesis of affordable phosphorus/carbon (APC) anode materials with an excellent electrochemical performance at a significantly reduced cost. The key to our success is a delicately designed, self-organized, strongly interactive porous P/C structure filled with sodium alginate binder, which maintains the structural integrity of anode and enhances the electrical contact of red P upon its volume variation via a dual protection from porous structure and strong surface interactions. The APC anodes hence present ultrahigh initial Coulombic efficiency (86.2%), excellent cycling stability, and superior rate capability. The industrially adaptable process and excellent electrochemical performance endow the novel APC nano/microspheres with promising applications in high-performance Na-ion batteries.

Carbon‐Based Alloy‐Type Composite Anode Materials toward Sodium‐Ion Batteries

“…Employing two types of carbon matrix can synergistically utilize the advantages of different materials, and enable the anodes to achieve superior electrochemical behavior . Zhou et al presented a typical integration of CNTs/graphene comodified RP via a scalable method, and this self‐standing ternary anode delivered a specific capacity 2112.9 mAh g −1 at 0.2 C during over 500 cycles, close to the theoretical value.…”

Recent Advances and Optimization Strategies on the Electrolytes for Hard Carbon and P‐Based Sodium‐Ion Batteries

“…P has a super high theoretical capacity of sodium storage (2596 mAh g −1 ; 3Na + P → Na 3 P) and a suitable insertion voltage (about 0.4 V vs Na/Na + ). [ 19,20,45,92 ] In addition, P has the advantages of large natural reserves and cost‐effective, which provides great potential for its practical application in SIBs. [ 11–13,15,93 ] Since the first report of BP was introduced as anode materials for LIBs.…”

“…As for RP materials, NaClO 4 and NaPF 6 as the sodium salts are widely used in SIBs. [ 19,20,28,111,106 ] The most accepted binary system electrolytes of RP anode materials mainly include PC/FEC, EC/PC, EC/DEC, EC/DMC, DMC/FEC with 1 m NaClO 4 or NaPF 6 . Other frequently used formulas are ternary solvents such as EC:DEC (1:1) + FEC, EC:PC (1:1) + FEC, EC:DMC (1:1) + FEC, EC:PC + DEC and EC:PC + DMC with 1 m NaClO 4 or NaPF 6 .…”

“…Another work by a dual‐protection strategy prepared P/C nano‐microspheres, and their successful large‐scale synthesis through an effective combination of ball‐milling and closed‐spray drying. [ 20 ]…”

Dual‐Function Sacrificing Template‐Directed Strategy for Constructing Hollow and Core‐Shell Nonstoichiometric Fe1–xS@C Microspheres Exhibiting Ultrafast Sodium Storage

“…In the long term, the large‐scale application of lithium ion batteries (LIBs) in portable electronic devices and electrical vehicles will be significantly constrained because of the resource limitation and cost concerns surrounding LIBs . As a promising alternative to LIBs, cost‐efficient sodium ion batteries (SIBs) have recently received intensive research interests owing to their analogous energy storage mechanism to LIBs . More importantly, sodium element with a much higher natural abundance than lithium, is widely distributed in the earth's crust and sea, which will greatly reduce the cost of SIBs.…”