A sustainable LiFePO4/graphite hybrid cathode capable of stepwise cation and anion storage

Lyu，Linlong1; Hu，Jing3; Lin，Dongmei1; Yao，Haimin1; Zhou，Limin2

2021-09-20

10.1016/j.electacta.2021.138936

ELECTROCHIMICA ACTA   影响因子和分区

0013-4686

Dual ion battery (DIB) with graphite cathode is a renewable energy storage system but suffers from low capacity. Addition of lithium ion battery (LIB) cathode to graphite cathode not only facilitates capacity increment but also serves as proof-of-concept for LIB-DIB hybridization. In this study, a hybrid cathode, incorporating a physical mixture of high working potential graphite and nontoxic lithium iron phosphate (LiFePO, LFP), is proposed and examined. The graphite interacts with anion and works as electrically conductive matrix. While additive LFP is active to cation, serving as capacity facilitator. Characterization results reveal that, during charging, the hybrid cathode starts with LFP delithiation in lower voltage region and finishes with anion intercalation in graphite at higher voltage region. During discharging, processes are reversed with stepwise anion deintercalation and cation insertion, without interfering individual constituent's proper functioning. The transfer of two polarity distinct ions inside the hybrid cathode maintains high independence, without any added kinetical difficulties. Such hybrid cathode is demonstrated to work stably with varied LFP-graphite proportions. The addition of 40 wt% LFP to graphite cathode shows doubled capacity and excellent long-term cyclability. And the hybrid cathode is also cyclable in a full cell configuration.

Anion storage Eco-friendly cathode Hybrid cathode In situ XRD

SCI ; EI

英语

通讯

WOS:000697484300001

20213110711035

Cathodes ; Iron compounds ; Lithium compounds ; Lithium-ion batteries ; Positive ions

CHEMISTRY

2-s2.0-85111542645

Scopus

1.Department of Mechanical Engineering,The Hong Kong Polytechnic University,Kowloon,Hung Hom,China
2.School of System Design and Intelligent Manufacturing,Southern University of Science and Technology,Shenzhen,518055,China
3.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Lyu，Linlong,Hu，Jing,Lin，Dongmei,et al. A sustainable LiFePO4/graphite hybrid cathode capable of stepwise cation and anion storage[J]. ELECTROCHIMICA ACTA,2021,391.

Lyu，Linlong,Hu，Jing,Lin，Dongmei,Yao，Haimin,&Zhou，Limin.(2021).A sustainable LiFePO4/graphite hybrid cathode capable of stepwise cation and anion storage.ELECTROCHIMICA ACTA,391.

Lyu，Linlong,et al."A sustainable LiFePO4/graphite hybrid cathode capable of stepwise cation and anion storage".ELECTROCHIMICA ACTA 391(2021).