scholarly journals Decomposition of Li2O2 as the Cathode Prelithiation Additive for Lithium-Ion Batteries without an Additional Catalyst and the Initial Performance Investigation

Author(s):  
Linghong Zhang ◽  
Sookyung Jeong ◽  
Nathan Reinsma ◽  
Kerui Sun ◽  
Derrick S Maxwell ◽  
...  

Abstract Compared to the graphite anode, Si and SiOx-containing anodes usually have a larger initial capacity loss (ICL) due to more parasitic reactions. The higher ICL of the anode can cause significant Li inventory loss in a full cell, leading to a compromised energy density. As one way to mitigate such Li inventory loss, Li2O2 can be used as the cathode prelithiation additive to provide additional lithium. However, an additional catalyst is usually needed to lower its decomposition potential. In this work, we investigate the use of Li2O2 as the cathode prelithiation additive without the addition of a catalyst. Li2O2 decomposition is first demonstrated in coin half-cells with a calculated capacity of 1180 mAh/g obtained from Li2O2 decomposition. We then further demonstrate successful Li2O2 decomposition in single-layer pouch (SLP) full cells and evaluate the initial electrochemical performance. Despite its moisture sensitivity, Li2O2 showed reasonable compatibility with dry-room handling. After dry-room handling, Li2O2 decomposition was observed with an onset potential of 4.29 V vs. SiOx anode in SLP cells. With Li2O2 addition, the utilization of the Li inventory from cathode active material was improved by 12.9%, and discharge DCR has reduced by 7% while the cells still deliver similar cell capacities.

2021 ◽  
Vol 1036 ◽  
pp. 35-44
Author(s):  
Ling Fang Ruan ◽  
Jia Wei Wang ◽  
Shao Ming Ying

Silicon-based anode materials have been widely discussed by researchers because of its high theoretical capacity, abundant resources and low working voltage platform,which has been considered to be the most promising anode materials for lithium-ion batteries. However,there are some problems existing in the silicon-based anode materials greatly limit its wide application: during the process of charge/discharge, the materials are prone to about 300% volume expansion, which will resultin huge stress-strain and crushing or collapse on the anods; in the process of lithium removal, there is some reaction between active material and current collector, which creat an increase in the thickness of the solid phase electrolytic layer(SEI film); during charging and discharging, with the increase of cycle times, cracks will appear on the surface of silicon-based anode materials, which will cause the batteries life to decline. In order to solve these problems, firstly, we summarize the design of porous structure of nanometer sized silicon-based materials and focus on the construction of three-dimensional structural silicon-based materials, which using natural biomass, nanoporous carbon and metal organic framework as structural template. The three-dimensional structure not only increases the channel of lithium-ion intercalation and the rate of ion intercalation, but also makes the structure more stable than one-dimensional or two-dimensional. Secondly, the Si/C composite, SiOx composite and alloying treatment can improve the volume expansion effection, increase the rate of lithium-ion deblocking and optimize the electrochemical performance of the material. The composite materials are usually coated with elastic conductive materials on the surface to reduce the stress, increase the conductivity and improve the electrochemical performance. Finally, the future research direction of silicon-based anode materials is prospected.


Author(s):  
Yanping Dang ◽  
Wangyu Liu ◽  
Weigui Xie ◽  
Weiping Qiu

Abstract The anode and cathode pieces are vital components of lithium-ion batteries. The coating surface density of active material is a significant parameter involved during the fabrication of electrodes and has considerable impact on battery performance. In this paper, anode and cathode pieces are prepared with different surface densities within the allowable range. The anode and cathode pieces are first graded respectively and then matched up according to different surface density ranges. Afterward, the electrodes are assembled with commercial polypropylene separator in 18,650 cell case and infused with electrolyte. The cathode is constituted with a mixture of nickel cobalt manganese (NCM) ternary material and lithium manganese oxide coated on aluminum foil, while the anode is composed of graphite coated on copper foil. The electrochemical performance and safety properties were tested to investigate the influence of the coating surface density of electrodes and optimize the electrochemical performance by regulating the matching surface density of electrodes. The results indicate that larger surface density of both cathode and anode can provide better battery consistency, while smaller surface density can contribute to better specific capacity and smaller capacity loss after cycling. Modest cost and superior properties can be achieved for lithium-ion batteries by reasonably matching the surface density of anodes and cathodes pieces.


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.


Author(s):  
Erfan Moyassari ◽  
Thomas Roth ◽  
Simon Kücher ◽  
C. C. Chang ◽  
Shang-Chieh Hou ◽  
...  

Abstract One promising way of compensating for the repeated volume expansion and contraction of silicon as an anode active material in lithium ion batteries (LIBs) is to embed silicon within a graphite matrix. Silicon-graphite (SiG) composites combine the advantageous properties of graphite, i.e., large electrical conductivity and high structural stability, with the advantageous properties of silicon, i.e., high theoretical capacity. Graphite has a much lower volume expansion upon lithiation (≈ 10%) than pure silicon (≈ 300%) and provides a mechanically stable matrix. Herein, we present an investigation into the electrochemical performance and thickness change behavior of porous SiG anode compositions with silicon contents ranging from 0 wt% to 20 wt%. The electrode composites were studied using two methods: in situ dilatometry for the thickness change investigation and conventional coin cells for the assessment of electrochemical performance. The measurements show that the initial thickness change of SiG electrodes increased significantly with the silicon content, but it leveled off during cycling for all compositions. There appears to be a correlation between silicon content and capacity loss, but no clear correlation between thickness change and capacity loss rate was found.


2017 ◽  
Vol 19 (38) ◽  
pp. 25905-25918 ◽  
Author(s):  
Florian Holtstiege ◽  
Andrea Wilken ◽  
Martin Winter ◽  
Tobias Placke

Active lithium loss (ALL) resulting in a capacity loss (QALL), which is caused by lithium consuming parasitic reactions like SEI formation, is a major reason for capacity fading and, thus, for a reduction of the usable energy density of lithium-ion batteries (LIBs).


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1467
Author(s):  
Xuanni Lin ◽  
Zhuoyi Yang ◽  
Anru Guo ◽  
Dong Liu

High energy density batteries with high performance are significantly important for intelligent electrical vehicular systems. Iron sulfurs are recognized as one of the most promising anodes for high energy density lithium-ion batteries because of their high theoretical specific capacity and relatively stable electrochemical performance. However, their large-scale commercialized application for lithium-ion batteries are plagued by high-cost and complicated preparation methods. Here, we report a simple and cost-effective method for the scalable synthesis of nanoconfined FeS in porous carbon (defined as FeS@C) as anodes by direct pyrolysis of an iron(III) p-toluenesulfonate precursor. The carbon architecture embedded with FeS nanoparticles provides a rapid electron transport property, and its hierarchical porous structure effectively enhances the ion transport rate, thereby leading to a good electrochemical performance. The resultant FeS@C anodes exhibit high reversible capacity and long cycle life up to 500 cycles at high current density. This work provides a simple strategy for the mass production of FeS@C particles, which represents a critical step forward toward practical applications of iron sulfurs anodes.


Sign in / Sign up

Export Citation Format

Share Document