Highly Stable and High Rate‐Performance Na‐Ion Batteries Using Polyanionic Anthraquinone as the Organic Cathode

Abstract

Sodium 9,10-anthraquinone-2,6-disulfonate (Na 2 AQ26DS), with polyanionic character and two OÀNa ionic bonds, is found to be ah ighly stable organic cathode in Na-ion batteries, delivering capacities of approximately 120 mAh g À1 for 300 cycles (50 mA g À1 )a nd around 99 mAh g À1 for 1000 cycles (1 Ag À1 ). These resultsa re the best performance reported to date for small-molecule, anthraquinone-basedo rganic cathodes in Li-, Na-, or K-ionbatteries.The rapidly-growing demands for electric vehicles anda"smart grid" require large-scale applicationso fr echargeable batteries.[1] Therefore, electrode materials in batteries that are low in cost, free of resourcel imitations, and environmentally friendly are highly desirable . [2] At present,r echargeable Li-ion batteries are approaching the ceiling of their energy density. [3] Moreover, the limited resources of Li (0.0017 wt %f or Li in the Earth's crust) and of the rare metals contained in cathodes, such as Ni, Co, Mn, also impedet heir large-scale application. [4] Organic electrode materials with extremelyl ow costs have attractedm ore and more attention as promisingn ext-generation energy-storagem aterials. More importantly,o rganic electrodes have been found capable to store abundant, cheap, and large-radius metal ions, such as Na + ,K + ,a nd Mg 2 + . [5] There are two main concerns for organic electrode materials under consideration for practical application. One is that organic electrode materials usually suffer from poor electronic conductivity and thus give unsatisfactory rate performance. [6] However,this problem can be largely solved by careful technological modifications. The other is that small-molecule organic materials, particularly for high-capacity organic cathodes, [7] show significant solubility in organic liquid electrolytes, [8] ultimately leadingt ot he poor cycling stability of organicb atteries.

Recent Advances of Two‐Dimensional (2 D) MXenes and Phosphorene for High‐Performance Rechargeable Batteries

“…In recent years, the problem of limited lithium reserves has become prominent with increasing demand for LIBs. Because of abundant sodium resources and the similar electrochemical intercalation–deintercalation mechanism to LIBs, SIBs have been identified as a promising replacement for next‐generation energy systems –. However, sodium ions have a much larger ionic radius of 0.102 nm than lithium ions (0.076 nm), indicating a low energy density and poor cycle life.…”

Analytical Measurements to Elucidate Structural Behavior of 2,5‐Dimethoxy‐1,4‐benzoquinone During Charge and Discharge

“…Moreover, the use of organic compounds as electrode materials is also promising . Using charge carriers other than Li ions, such as sodium, potassium, magnesium, calcium, aluminum, or molecular ions, is another method to develop sustainability in society. The development of systems that are completely free of scarce metal elements, including a scarce metal‐free charge carrier, will have a significant impact in a society that is heavily dependent on electricity and its consumption.…”

Construction of a Poly(anthraquinone Sulfide)/Carbon Nanotube Composite with Enhanced Li‐ion Storage Capacity

“…[5] In particular, carbonyl compounds, and especially quinone compounds, have emerged among the most promising candidate organic energy storage materials due to their advanta-geously high theoretical energy density, fast speed, and good reaction reversibility . [6][7] Moreover, the presence of two carbonyl groups enables the anthraquinone materials to participate in multi-electron reactions [8] and, thus, obtain a higher specific capacity [9] than that of the presently-used inorganic materials. [10] Quinone [11] can be used as the negative electrode material of lithium-ion batteries, which have a suitable lithium storage potential of 2-3 V. [12] However, although most quinone compounds have a high theoretical capacity of � 300 mA h g À 1 , they continue to exhibit problems such as high solubility in organic electrolytes and poor electronic conductivity, thus leading to a decrease in cycle performance.…”