26 Sep 02:00
by Feifan Zhang,
Gege Wang,
Jing Wu,
Xiaowei Chi,
Yu Liu
Benefiting from the coordination stabilization of PAL ligands, the highly reversible high-voltage solid-phase Mn3+/Mn2+ redox couple is realized in near-neutral aqueous Zn−Mn batteries.
Abstract
Aqueous Zn−Mn battery has been considered as the most promising scalable energy-storage system due to its intrinsic safety and especially ultralow cost. However, the traditional Zn−Mn battery mainly using manganese oxides as cathode shows low voltage and suffers from dissolution/disproportionation of the cathode during cycling. Herein, for the first time, a high-voltage and long-cycle Zn−Mn battery based on a highly reversible organic coordination manganese complex cathode (Manganese polyacrylate, PAL−Mn) was constructed. Benefiting from the insoluble carboxylate ligand of PAL−Mn that can suppress shuttle effect and disproportionationation reaction of Mn3+ in a mild electrolyte, Mn3+/Mn2+ reaction in coordination state is realized, which not only offers a high discharge voltage of 1.67 V but also exhibits excellent cyclability (100 % capacity retention, after 4000 cycles). High voltage reaction endows the Zn−Mn battery high specific energy (600 Wh kg−1 at 0.2 A g−1), indicating a bright application prospect. The strategy of introducing carboxylate ligands in Zn−Mn battery to harness high-voltage reaction of Mn3+/Mn2+ well broadens the research of high-voltage Zn−Mn batteries under mild electrolyte conditions.
11 Jun 12:19
by Siyuan Pan,
Junwei Han,
Yiqiao Wang,
Zhenshen Li,
Fanqi Chen,
Yong Guo,
Zishan Han,
Kefeng Xiao,
Zhichun Yu,
Mengying Yu,
Shichao Wu,
Da‐Wei Wang,
Quan‐Hong Yang
A layered conductive polyaniline (LCP) coating is built from a bottom-up polymer design strategy for Si anodes. The in situ formation of LCP-integrated solid electrolyte interphase (SEI) with uniform structure and flexible mechanical property enhances the stability of the electrode–electrolyte interface.
Abstract
Tackling the huge volume expansion of silicon (Si) anode desires a stable solid electrolyte interphase (SEI) to prohibit the interfacial side reactions. Here, a layered conductive polyaniline (LCP) coating is built on Si nanoparticles to achieve high areal capacity and long lifespan. The conformal LCP coating stores electrolyte in interlamination spaces and directs an in situ formation of LCP-integrated hybrid SEI skin with uniform distribution of organic and inorganic components, enhancing the flexibility of the SEI to buffer the volume changes and maintaining homogeneous ion transport during cycling. As a result, the Si anode shows a remarkable cycling stability under high areal capacity (≈3 mAh cm−2) after 150 cycles and good rate performance of 942 mAh g−1 at 5 A g−1. This work demonstrates the great potential of regulating the SEI properties by a layered polymer-directing SEI formation for the mechanical and electrochemical stabilization of Si anodes.
21 Aug 02:45
by Haochuan Zhang,
Jingru Luo,
Miao Qi,
Shiru Lin,
Qi Dong,
Haoyi Li,
Nicholas Dulock,
Christopher Povinelli,
Nicholas Wong,
Wei Fan,
Junwei Lucas Bao,
Dunwei Wang
A critical challenge toward realizing Li metal anode has been the lack of stable SEI between Li and the electrolyte. We report an approach of using oxygen to induce unique decompositions of organic phosphate solvent, where simple reactions favor the formation of a stable SEI. This method permits repeated Li stripping/plating on Li metal in a flame retardant electrolyte. The results promise safe operations of Li in next generation batteries.
Abstract
Lithium metal anode holds great promises for next-generation battery technologies but is notoriously difficult to work with. The key to solving this challenge is believed to lie in the ability of forming stable solid-electrolyte interphase (SEI) layers. To further address potential safety issues, it is critical to achieve this goal in nonflammable electrolytes. Building upon previous successes in forming stable SEI in conventional carbonate-based electrolytes, here we report that reversible Li stripping/plating could be realized in triethyl phosphate (TEP), a known flame retardant. The critical enabling factor of our approach was the introduction of oxygen, which upon electrochemical reduction induces the initial decomposition of TEP and produces Li3PO4 and poly-phosphates. Importantly, the reaction was self-limiting, and the resulting material regulated Li plating by limiting dendrite formation. In effect, we obtained a functional SEI on Li metal in a nonflammable electrolyte. When tested in a symmetric Li∥Li cell, more than 300 cycles of stripping/plating were measured at a current density of 0.5 mA cm−2. Prototypical Li-O2 and Li-ion batteries were also fabricated and tested to further support the effectiveness of this strategy. The mechanism by which the SEI forms was studied by density functional theory (DFT), and the predictions were corroborated by the successful detection of the intermediates and products.
08 Apr 02:29
by Jingru Li, Han Su, Min Li, Jiayuan Xiang, Xianzhang Wu, Sufu Liu, Xiuli Wang, Xinhui Xia, Changdong Gu, and Jiangping Tu
ACS Applied Materials & Interfaces
DOI: 10.1021/acsami.1c02868
Open Access
  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
