Pretreatment Process Before Heat Pyrolysis of Plant‐based Precursors Paving Way for Fabricating High‐Performance Hard Carbon for Sodium‐Ion Batteries

Abstract

The increasing demand for sodium‐ion batteries has risen due to sodium resources that are inexpensive and abundant compared with its counterpart of lithium‐ion batteries. Development of anode materials with high performance is central issue for sodium‐ion batteries. Plant‐based hard carbon material is a promising anode material for sodium ion batteries due to its green preparation process, favorable ions transport channel, and special porous structure. Previous studies have not systematically correlated the material's inherent structure limitation with its electrochemical properties, resulting in a complex classification and a lack selection of pretreatment methods. In this review, the intrinsic limitations in the structure of plant‐based precursors are divided into four parts, including impure components, single chemical structure, uncontrollable crystalline texture, and irregular porous structure. The previous pretreatment methods are reclassified, including purification component aiming at plant‐based precursors, optimized structure, and precabornized process aiming at intermediate products. Furthermore, the pretreatment strategies are discussed according to the preferred structures of plant‐based hard carbon and the relationship between structure and performance is systematically expounded. This review provides deep understanding of the mechanism of pretreatment and a guide for selecting appropriate pretreatment strategies to optimize the structure of plant‐based hard carbon for sodium ion batteries.

Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries

“…4 , the strategies for improving rate performance of cellulose-based carbon materials are summarized at the cellulose materials level. Our group discussed the inherent limitations in cellulose-based materials, which encompass impurities within components, a singular chemical structure, uncontrolled crystalline texture, and irregular porous architecture, and further provided an opinion that a pretreatment strategy is necessary to fabricate cellulose-derived materials [ 177 ]. Here, two strategies including building robust charge transport network and optimizing valid ion transport pathways, have been developed to obtain the higher rate capacity of cellulose-derived carbon materials at cellulose materials level.…”

Progress Of Low-Temperature Carbonization of Cellulose as Anode Material for Sodium-Ion Batteries

“…After more than 50 years of research, sodium ions cannot be embedded in graphite layers to a large extent due to their large radius but can be reversibly embedded in some soft or hard carbon materials. The basic structure of SIBs can be divided into the following parts: Structure and working principle of sodium-ion batteries [22] (1) Positive electrode materials: the positive electrode materials of SIBs mainly include transition metal oxides, polyanionic compounds, Prussian blue analogues, layered oxides, fluoride and organic compounds, etc.…”

“…Figure 3.Structure and working principle of sodium-ion batteries[22] (1) Positive electrode materials: the positive electrode materials of SIBs mainly include transition metal oxides, polyanionic compounds, Prussian blue analogues, layered oxides, fluoride and organic compounds, etc. (2) Negative electrode materials: Negative electrode active materials are generally selected from carbon materials, such as natural graphite, artificial graphite, intermediate phase carbon microspheres, etc., which have excellent cycling stability.…”

Woven fabric-based separators with low tortuosity for sodium-ion batteries

“…3,4 Hence, the electrolyte transport properties play a decisive role in improving the electrochemical performance and safety of SIBs that effect uniform distribution of ion concentration and current density. Previously, tremendous work focused on the optimized electrodes' ion transport network to achieve high-performance batteries, 5,6 while less emphasis has been placed on constructing an advanced separator.…”