High?Defect?Density Graphite for Superior?Performance Aluminum?Ion Batteries with Ultra?Fast Charging and Stable Long Life

• 作者: Jisu Kim Michael Ruby Raj Gibaek Lee
• 来源期刊: 纳微快报（英文版）
• 年，卷（期）: 2021,（11）
• 页码范围: 168-189
• 页数: 22页
• 语种: 英文

摘要

Rechargeable aluminum-ion bat teries (AIBs) are a new generation of low-cost and large-scale electrical energy storage systems. However, AIBs suffer from a lack of reliable cathode materials with insufficient intercalation sites, poor ion-conducting channels, and poor diffusion dynamics of large chloroaluminate anions -(AlCl4? and -Al2Cl7?). To address these issues, surfacemodified graphitic carbon materials [i.e., acidtreated expanded graphite (AEG) and base-etchedgraphite (BEG)] are developed as novel cathode materials for ultra-fast chargeable AIBs. AEG has more turbostratically ordered structure covered with abundant micro- to nano-sized pores on the surface structure and expanded interlayer distance (d002 = 0.3371 nm) realized by surface treatment of pristine graphite with acidic media, which can be accelerated the diffusion dynamics and efficient -AlCl4? ions (de)-intercalation kinetics. The AIB system employing AEG exhibits a specific capacity of 88.6 mAh -g?1 (4 A -g?1) and ～ 80 mAh -g?1 at an ultra-high current rate of 10 A -g?1 (～ 99.1％ over 10,000 cycles). BEG treated with KOH solution possesses the turbostratically disordered structure with high density of defective sites and largely expanded d-spacing (d002 = 0.3384 nm) for attracting and uptaking more -AlCl4? ions with relatively shorter penetration depth. Impressively, the AIB system based on the BEG cathode delivers a high specific capacity of 110 mAh -g?1 (4 A -g?1) and ～ 91 mAh -g?1 (～ 99.9％ over 10,000 cycles at 10 A -g?1). Moreover, the BEG cell has high energy and power densities of 247 Wh -kg?1 and 44.5 kW -kg?1. This performance is one of the best among the AIB graphitic carbon materials reported for chloroaluminate anions storage performance. This finding provides great significance for the further development of rechargeable AIBs with high energy, high power density, and exceptionally long life.