Lian-Wei Luo

Bio: Lian-Wei Luo is an academic researcher from Shaanxi Normal University. The author has contributed to research in topics: Conjugated microporous polymer & Cathode. The author has an hindex of 2, co-authored 4 publications receiving 25 citations.

Tailoring the linking patterns of polypyrene cathodes for high-performance aqueous Zn dual-ion batteries

Abstract: Although the utilization of mildly acidic electrolyte can enhance the stability and reversibility of Zn anode, it is still challenging to achieve long cycling life for aqueous Zn batteries at low currents, due to the structural instability of cathode materials during the charge/discharge processes. Herein, we report a series of polypyrenes with different linking patterns and electronic structures as Cl−-hosting organic cathodes for aqueous Zn dual-ion batteries (AZDIBs). The comparative study demonstrates that the electronic structures are pivotal to the redox activity of the polypyrenes, which can be tuned by altering the linking patterns on the pyrene unit. Owing to the high surface area, the highly delocalized HOMO distribution, the high HOMO level and the narrow band gap, the polymer CLPy with 1,3,6,8-linking pattern delivers a much higher capacity of 180 mA h g−1 than the two linear counterparts (24 mA h g−1 for LPy-1 and 44 mA h g−1 for LPy-2). Impressively, CLPy exhibits ultra-stable cyclabilities with the capacity retentions of 97.4% after 800 cycles at 50 mA g−1 and 96.4% after 38 000 cycles at 3 A g−1. CLPy also shows a low self-discharge rate with around 90% capacity retention after resting for 28 days. The excellent electrochemical performance demonstrates that CLPy can be a promising cathode material for high-performance AZDIBs.

A redox-active conjugated microporous polymer cathode for high-performance lithium/potassium-organic batteries

Abstract: Organic redox-active materials have emerged as a class of electrode materials for rechargeable batteries due to their high redox activity, low cost, structure diversity and flexibility. However, the high solubility of organic small molecules in organic electrolytes commonly leads to the fast capacity decay with cycling. Herein, we report a redox-active conjugated microporous polymer of poly(pyrene-co-anthraquinone) (PyAq) cathode material consisting of pyrene and anthraquinone units. Benefiting from the highly cross-linked polymer structure with insoluble nature in organic electrolytes, the high surface area and the plentiful redox-active carbonyl groups, the PyAq cathode demonstrates outstanding electrochemical performances for both lithium-ion batteries (LIBs) and potassium-ion batteries (KIBs). Specifically, the PyAq cathode for LIBs delivers a high reversible capacity of 169 mAh g−1 at the current density of 20 mA g−1, a high rate capability (142 mAh g−1 at 1000 mA g−1) and an excellent cycling stability for 4000 cycles. Additionally, the PyAq cathode for KIBs also exhibits a high reversible capacity of 143 mAh g−1 with a long cycling life over 800 cycles. The excellent electrochemical performance demonstrates that the newly developed PyAq could be an attractive cathode material for the advanced energy storage technologies.

Design of a Solid Electrolyte Interphase for Aqueous Zn Batteries

Abstract: Aqueous Zn batteries are challenged by water decomposition and dendrite growth due to the absence of a dense Zn-ion conductive solid electrolyte interphase (SEI) to inhibit the hydrogen evolution reaction (HER). Here, we design a low-concentration aqueous Zn(OTF)2 -Zn(NO3 )2 electrolyte to in situ form a robust inorganic ZnF2 -Zn5 (CO3 )2 (OH)6 -organic bilayer SEI, where the inorganic inner layer promotes Zn-ion diffusion while the organic outer layer suppresses water penetration. We found that the insulating Zn5 (OH)8 (NO3 )2 ⋅2 H2 O layer is first formed on the Zn anode surface by the self-terminated chemical reaction of NO3 - with Zn2+ and OH- generated via HER, and then it transforms into Zn-ion conducting Zn5 (CO3 )2 (OH)6 , which in turn promotes the formation of ZnF2 as the inner layer. The organic-dominated outer layer is formed by the reduction of OTF- . The in situ formed SEI enables a high Coulombic efficiency (CE) of 99.8 % for 200 h in Ti∥Zn cells, and a high energy density (168 Wh kg-1 ) with 96.5 % retention for 700 cycles in Zn∥MnO2 cells with a low Zn/MnO2 capacity ratio of 2:1.

A Novel Low-Strain Phosphate Cathode for High-Rate and Ultralong Cycle-Life Potassium-Ion Batteries.

Abstract: Most potassium-ion battery (PIB) cathode materials have deficient structural stability because of the huge radius of potassium ion, leading to inferior cycling performance. In this work, we report the controllable synthesis of a novel low-strain phosphate material K 3 (VO)(HV 2 O 3 )(PO 4 ) 2 (HPO 4 ) (denoted KVP) nanorulers as an efficient cathode for PIBs. The as-synthesized KVP nanoruler cathode can exhibit an initial reversible capacity of 80.6 mAh g -1 under 20 mA g -1 , with a large average working potential of 4.11 V. It can also manifest an excellent rate property of 54.4 mAh g -1 under 5 A g -1 , with an exceedingly high capacity preservation of 92.1% over 2500 cycles. The outstanding potassium storage capability of KVP nanoruler cathode originates from low-strain K + uptake/removal mechanism, inherent semiconductor characteristic, and small K + migration energy barrier. The high energy density and prolonged cyclic stability of KVP nanorulers//polyaniline-intercalated layered titanate full battery verifies the superiority of KVP nanoruler cathode in PIBs. Our results show that this high-voltage low-strain phosphate material is a competitive cathode for PIBs and will draw more attention and investigations in the future.

Molecular Engineering of Covalent Organic Framework Cathodes for Enhanced Zinc-Ion Batteries

Abstract: Covalent organic frameworks (COFs) are potentially promising electrode materials for electrochemical charge storage applications thanks to their pre-designable reticular chemistry with atomic precision, allowing precise control of pore size, redox-active functional moieties, and stable covalent frameworks. However, studies on the mechanistic and practical aspects of their zinc-ion storage behavior are still limited. In this study, a strategy to enhance the electrochemical performance of COF cathodes in zinc-ion batteries (ZIBs) by introducing the quinone group into 1,4,5,8,9,12-hexaazatriphenylene-based COFs is reported. Electrochemical characterization demonstrates that the introduction of the quinone groups in the COF significantly pushes up the Zn2+ storage capability against H+ and elevates the average (dis-)charge potential in aqueous ZIBs. Computational and experimental analysis further reveals the favorable redox-active sites that host Zn2+ /H+ in COF electrodes and the root cause for the enhanced electrochemical performance. This work demonstrates that molecular engineering of the COF structure is an effective approach to achieve practical charge storage performance.

Challenges and perspectives of covalent organic frameworks for advanced alkali-metal ion batteries

Abstract: Covalent organic frameworks (COFs) are a class of porous crystalline polymers that have been widely investigated in various fields, including energy storage, photo/electrocatalysis, drug delivery. The covalent-bond interconnection allows COFs extraordinary chemical and thermal stability, and the porous structure ensures a high ion-diffusion coefficient. These merits compensate for the drawbacks of organic electrodes that are easy to dissolve and have low charge conductivity, and promote the development of novel electrode materials with excellent performance, environmental friendliness, and low price. However, the application of COFs also encountered many problems, such as poor electronic conductivity due to the large band gap. Moreover, in some three-dimensional (3D) COFs and stacked two-dimensional (2D) COFs, the huge crystal structure, aligned ultralong channels, and numerous crystal defects usually impede ion transport, and the large molecular weights of COFs generally decrease the specific capacities. These issues are urgently needed to be solved. Here in this review, we summarize the latest progress, core challenges and coping strategies concerning with the use of COFs in alkali-metal ion batteries, discuss the impact of material structure on energy storage, and propose strategies for the construction of high-performance COF-based electrodes.

All-Organic Rechargeable Battery with Reversibility Supported By “Water-in-Salt” Electrolyte

Abstract: Rechargeable batteries with organic electrodes are preferred to those with transition-metal-containing electrodes for their environmental friendliness, and resource availability, but all such batteries reported to date are based on organic electrolytes, which raise concerns of safety and performance. Here an aqueous-electrolyte all-organic rechargeable battery is reported, with a maximum operating voltage of 2.1 V, in which polytriphenylamine (PTPAn) and 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA)-derived polyimide (PNTCDA) serve as cathode and anode material, respectively. A key feature of the design is use of a "water-in-salt" electrolyte to bind "free" water; this impedes the side reaction of water oxidation, thereby enabling excellent reversibility in aqueous solution. The battery can deliver a maximum energy density of 52.8 Wh kg-1 , which is close to most of the all-organic batteries with organic electrolytes. The battery exhibits a supercapacitor-like high power of 32 000 W kg-1 and a long cycle life (700 cycles with capacity retention of 85 %), due to the kinetics not being limited by ion diffusion at either electrode.