Microstructure regulation of pitch-based soft carbon anodes by iodine treatment towards high-performance potassium-ion batteries

Sun

et al. 2022

Adv Funct Materials

119

Coal features low‐cost and high carbon yield and is considered as a promising precursor for carbon anode of sodium‐ion batteries (SIBs) and sodium‐ion capacitors (SICs). Regulation of microcrystalline state and pore configuration of coal structure during thermal transformation is key to boost Na+ storage behavior. Herein, a facile strategy is reported to create abundant closed pores in anthracite‐derived carbon that greatly improves Na+ plateau storage. An altered thermal transformation pathway of chemical activation followed by high‐temperature carbonization is adopted to achieve the conversion of open nanopores and ordered carbon crystallite into closed pores surrounded by short‐range carbon structures. The optimized sample delivers a large reversible capacity of 308 mAh g–1 that is dominantly contributed by the low‐voltage plateau process. Experimental results reveal the enhanced pore‐filling mechanism in the developed closed pores. Benefitting from the improved plateau behavior, the constructed SIB delivers a high‐energy density of 231.2 Wh kg–1 with an average voltage of 3.22 V; the assembled full‐carbon SIC shows high energy and power densities (101.8 Wh kg–1 and 2.9 kW kg–1). This work provides a universal thermal transformation approach for designing high‐performance carbon anode with closed porosity from low‐cost and highly aromatic precursors.

Section: Resultsmentioning

confidence: 83%

Altering Thermal Transformation Pathway to Create Closed Pores in Coal‐Derived Hard Carbon and Boosting of Na⁺ Plateau Storage for High‐Performance Sodium‐Ion Battery and Sodium‐Ion Capacitor

Sun

et al. 2022

Adv Funct Materials

119

“…The kinetics and K storage behaviors of the PC- x anodes were further studied via the galvanostatic intermittent titration technique (GITT, Figure S10). Compared with PC-900 and PC-1100, PC-700 provides the lowest polarization potential during (de)potassiation, indicating that low-temperature pyrolytic carbon possesses better kinetic properties (Figure a, b). Moreover, the diffusion coefficient ( D K + ) as a function of voltage is shown in Figure c,d.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, although inferior to PC-900-CMC, the high ICE (71.5%) of the PC-900-PVdF electrode still is at the leading level in the carbon anode, indicating the success of structural modulation. 42,45,52 The above results suggest that the integrated design of synergistic material structure regulation and binder optimization is necessary to prepare high-performance and practical PIB electrodes.…”

Section: Electrochemical Measurementsmentioning

confidence: 95%

Integrated Design from Microstructural Engineering to Binder Optimization Enabling a Practical Carbon Anode with Ultrahigh ICE and Efficient Potassium Storage

Yan

Ren

ACS Appl. Mater. Interfaces

et al. 2022

Potassium-ion batteries (PIBs) are emerging as a powerful alternative to lithium-ion battery systems in large-scale energy storage owing to plentiful resources. Nevertheless, pursuing high-yield anode materials with high initial Coulombic efficiency (ICE) and superior rate capability is still one of the most critical challenges in practical application. Herein, an integrated electrode (PC-x) derived from a petroleum coke precursor (carbon residue rate as high as 89%) is regulated from microstructural engineering to binder optimization devoting to high ICE and efficient potassium storage. Excitingly, with a strong assist from a sodium carboxymethyl cellulose (CMC) binder, the PC-900 anode displays an ultrahigh ICE of 80.5%, one of the highest values reported for PIB carbon anodes. Simultaneously, the PC-900 anode submits a high capacity (304.3 mAh g–1), superb rate (138.2 mAh g–1 at 10C), and excellent stability. Furthermore, the full cell exhibits an outstanding rate and cycling performance (210.7 mAh g–1 at 0.5C), confirming its large-scale application prospects. The ultrahigh ICE and excellent performance are mainly attributable to the beneficial microstructures (low surface area, functional group content, and larger interlayer spacing) created by microstructural engineering. Meanwhile, binder optimization also plays a crucial role in reducing the irreversible capacity and interface impedance, further improving the ICE and rate capability. Importantly, mechanism analysis confirms two-stage K+ storage behavior: reversible adsorption at edges and defects (>0.25 V) and intercalation into crystalline layers (<0.25 V). This work provides an efficient and easily scalable electrode design strategy for future practical applications of PIBs.

“…Expanded layer spacing and increased defects contribute to the K‐storage capacity of pitch‐based carbon. Liu et al [178] . added iodine to the coal tar pitch, effectively crosslinking the aromatics via alkyl‐bridge bonds and then reducing interactions between aromatic structures during carbonization, resulting in increased layer spacing and defect sites.…”

Section: Research Trends Of Pitch‐based Carbon Anodes In Lib Sib and Pibmentioning

confidence: 99%

Synthesis Strategies and Applications for Pitch‐Based Anode: From Industrial By‐Products to Power Sources

Yan

Kong

et al. 2022

The Chemical Record

It is significant for saving energy to manufacture superb-property batteries. Carbon is one of the most competitive anode materials in batteries, but it is hard for commercial graphite anodes to meet the increasingly higher energy-storage requirements. Moreover, the price of other better-performing carbon materials (such as graphene) is much higher than graphite, which is not conducive to massive production. Pitch, the cheap by-product in the petroleum and coal industries, has high carbon content and yield, making it possible for commercialization. Developing pitch-based anodes can not only lower raw material costs but also realize the pitch's high value-added utilization. We comprehensively reviewed the latest synthesis strategies of pitch-derived materials and then introduced their application and research progress in lithium, sodium, and potassium ion batteries (LIBs, SIBs, and PIBs). Finally, we summarize and suggest the pitch's development trend for anodes and in other fields.