Nanoparticle Emissions From Metal-Assisted Chemical Etching of Silicon Nanowires for Lithium Ion Batteries

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Fenfen Wang ◽  
Xianfeng Gao ◽  
Lulu Ma ◽  
Chris Yuan

As one of the most promising anode materials for high-capacity lithium ion batteries (LIBs), silicon nanowires (SiNWs) have been studied extensively. The metal-assisted chemical etching (MACE) is a low-cost and scalable method for SiNW synthesis. Nanoparticle emissions from the MACE process, however, are of grave concerns due to their hazardous effects on both occupational and public health. In this study, both airborne and aqueous nanoparticle emissions from the MACE process for SiNWs with three sizes of 90 nm, 120 nm, and 140 nm are experimentally investigated. The prepared SiNWs are used as anodes of LIB coin cells, and the experimental results reveal that the initial discharge and charge capacities of LIB electrodes are 3636 and 2721 mAh g−1 with 90 nm SiNWs, 3779 and 2712 mAh g−1 with 120 nm SiNWs, and 3611 and 2539 mAh g−1 with 140 nm SiNWs. It is found that for 1 kW h of LIB electrodes, the MACE process for 140 nm SiNWs produces a high concentration of airborne nanoparticle emissions of 2.48 × 109 particles/cm3; the process for 120 nm SiNWs produces a high mass concentration of aqueous particle emissions, with a value of 9.95 × 105 mg/L. The findings in this study can provide experimental data of nanoparticle emissions from the MACE process for SiNWs for LIB applications and can help the environmental impact assessment and life cycle assessment of the technology in the future.

NANO ◽  
2020 ◽  
Vol 15 (06) ◽  
pp. 2050076
Author(s):  
Fang Sun ◽  
Zhiyuan Tan ◽  
Zhengguang Hu ◽  
Jun Chen ◽  
Jie Luo ◽  
...  

Silicon is widely studied as a high-capacity lithium-ion battery anode. However, the pulverization of silicon caused by a large volume expansion during lithiation impedes it from being used as a next generation anode for lithium-ion batteries. To overcome this drawback, we synthesized ultrathin silicon nanowires. These nanowires are 1D silicon nanostructures fabricated by a new bi-metal-assisted chemical etching process. We compared the lithium-ion battery properties of silicon nanowires with different average diameters of 100[Formula: see text]nm, 30[Formula: see text]nm and 10[Formula: see text]nm and found that the 30[Formula: see text]nm ultrathin silicon nanowire anode has the most stable properties for use in lithium-ion batteries. The above anode demonstrates a discharge capacity of 1066.0[Formula: see text]mAh/g at a current density of 300[Formula: see text]mA/g when based on the mass of active materials; furthermore, the ultrathin silicon nanowire with average diameter of 30[Formula: see text]nm anode retains 87.5% of its capacity after the 50th cycle, which is the best among the three silicon nanowire anodes. The 30[Formula: see text]nm ultrathin silicon nanowire anode has a more proper average diameter and more efficient content of SiOx. The above prevents the 30[Formula: see text]nm ultrathin silicon nanowires from pulverization and broken during cycling, and helps the 30[Formula: see text]nm ultrathin silicon nanowires anode to have a stable SEI layer, which contributes to its high stability.


Author(s):  
Shaohua Lu ◽  
Weidong Hu ◽  
Xiaojun Hu

Due to their low cost and improved safety compared to lithium-ion batteries, sodium-ion batteries have attracted worldwide attention in recent decades.


2021 ◽  
Vol 10 (1) ◽  
pp. 210-220
Author(s):  
Fangfang Wang ◽  
Ruoyu Hong ◽  
Xuesong Lu ◽  
Huiyong Liu ◽  
Yuan Zhu ◽  
...  

Abstract The high-nickel cathode material of LiNi0.8Co0.15Al0.05O2 (LNCA) has a prospective application for lithium-ion batteries due to the high capacity and low cost. However, the side reaction between the electrolyte and the electrode seriously affects the cycling stability of lithium-ion batteries. In this work, Ni2+ preoxidation and the optimization of calcination temperature were carried out to reduce the cation mixing of LNCA, and solid-phase Al-doping improved the uniformity of element distribution and the orderliness of the layered structure. In addition, the surface of LNCA was homogeneously modified with ZnO coating by a facile wet-chemical route. Compared to the pristine LNCA, the optimized ZnO-coated LNCA showed excellent electrochemical performance with the first discharge-specific capacity of 187.5 mA h g−1, and the capacity retention of 91.3% at 0.2C after 100 cycles. The experiment demonstrated that the improved electrochemical performance of ZnO-coated LNCA is assigned to the surface coating of ZnO which protects LNCA from being corroded by the electrolyte during cycling.


Carbon ◽  
2013 ◽  
Vol 64 ◽  
pp. 158-169 ◽  
Author(s):  
Shuangqiang Chen ◽  
Peite Bao ◽  
Linda Xiao ◽  
Guoxiu Wang

Author(s):  
Fenfen Wang ◽  
Xianfeng Gao ◽  
Lulu Ma ◽  
Chris Yuan

Abstract Silicon nanowires (SiNWs) with three different average diameters of 90, 120, and 140 nm were synthesized by a metal-assisted chemical etching (MACE) method. Environmental sustainability of the MACE process was studied by investigating material consumptions, gas emissions, and silver nanoparticle concentrations in nitric acid solutions for 1 g of SiNWs and 1 kW h of lithium-ion battery (LIB) electrodes. It was found that the process for 90 nm SiNWs has the best sustainability performance compared with the other two processes. Specifically, in this study for 1 g of 90 nm SiNWs, 8.845 g of Si wafer is consumed, 1.09 g of H2 and 1.04 g of NO are produced, and 54.807 mg of Ag nanoparticles are found in the HNO3 solution. Additionally, for 1 kW h of LIB electrodes, the process for 90 nm SiNWs results in 1.943 kg of Si wafer consumption, 239.455 g of H2 and 239.455 g of NO emissions, and 12.040 g of Ag nanoparticles concentrations. By quantitatively investigating the material consumptions and emissions, this study assesses the sustainability performance of the MACE process for synthesizing SiNWs for use in LIBs, and thus it provides process data for the analysis and the development of sustainable production methods for SiNWs and similar anode materials for next-generation LIBs.


ACS Omega ◽  
2020 ◽  
Vol 5 (27) ◽  
pp. 16440-16447
Author(s):  
Minghang Xu ◽  
Jiaojiao Ma ◽  
Guiling Niu ◽  
Hongxun Yang ◽  
Mengfei Sun ◽  
...  

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Lu Wang ◽  
Junwei Han ◽  
Debin Kong ◽  
Ying Tao ◽  
Quan-Hong Yang

Abstract Lithium-ion batteries (LIBs), which are high-energy-density and low-safety-risk secondary batteries, are underpinned to the rise in electrochemical energy storage devices that satisfy the urgent demands of the global energy storage market. With the aim of achieving high energy density and fast-charging performance, the exploitation of simple and low-cost approaches for the production of high capacity, high density, high mass loading, and kinetically ion-accessible electrodes that maximize charge storage and transport in LIBs, is a critical need. Toward the construction of high-performance electrodes, carbons are promisingly used in the enhanced roles of active materials, electrochemical reaction frameworks for high-capacity noncarbons, and lightweight current collectors. Here, we review recent advances in the carbon engineering of electrodes for excellent electrochemical performance and structural stability, which is enabled by assembled carbon architectures that guarantee sufficient charge delivery and volume fluctuation buffering inside the electrode during cycling. Some specific feasible assembly methods, synergism between structural design components of carbon assemblies, and electrochemical performance enhancement are highlighted. The precise design of carbon cages by the assembly of graphene units is potentially useful for the controlled preparation of high-capacity carbon-caged noncarbon anodes with volumetric capacities over 2100 mAh cm−3. Finally, insights are given on the prospects and challenges for designing carbon architectures for practical LIBs that simultaneously provide high energy densities (both gravimetric and volumetric) and high rate performance.


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