Elsevier

Nano Energy

Volume 12, March 2015, Pages 305-313
Nano Energy

Rapid communication
Synthesis of phase-pure Li2MnSiO4@C porous nanoboxes for high-capacity Li-ion battery cathodes

https://doi.org/10.1016/j.nanoen.2014.12.021Get rights and content

Highlights

  • Uniform Li2MnSiO4@C porous nanoboxes with a pure phase were synthesized for the first time.

  • Simultaneous control of the phase purity and the nanoscale architecture of Li2MnSiO4 was achieved.

  • A novel wet-chemistry associated solid-state reaction for the synthesis of Li2MnSiO4 was developed.

  • As-prepared Li2MnSiO4-based nanocomposites show high capacities as LIB cathode.

Abstract

Li2MnSiO4@C porous nanoboxes have been synthesized via a wet-chemistry associated solid-state reaction method. The uniqueness of this material is the hollow nanostructure with a well-crystalline porous shell composed of phase-pure Li2MnSiO4 nanocrystals, which has not been reported previously. As evidenced by powder X-ray diffraction patterns and transmission electron microscopy images, the high phase purity and porous nanobox architecture were achieved via monodispersed MnCO3@SiO2 core–shell nanocubes with controlled shell thickness. Nanocomposite of Li2MnSiO4@C and reduced graphene oxide nanosheets demonstrated excellent performance as high-capacity cathode materials for Li-ion batteries.

Introduction

Due to the growing demand for long-lasting, rechargeable Li-ion batteries for various applications ranging from portable electronic devices to electric vehicles, significant efforts have been devoted to increase the capacities of cathode materials [1], [2], [3], [4]. Besides improving the capacities of commercially available materials to close to their theoretical limits [5], [6], the development of new compounds with high theoretical capacities is of great interest [7], [8], [9], [10], [11], [12], [13].

In recent years, lithium orthosilicate-related compounds, Li2MSiO4 (M=Mn2+, Fe2+, and Co2+), have received significant interest as one of the most promising alternative cathodes [14], [15], [16], [17], [18], [19], [20]. Compared to the conventional cathode materials, such as layered LiCoO2, spinel LiMn2O4 and olivine-type LiMPO4 (M=Mn2+, Fe2+, and Co2+), Li2MSiO4 material has the advantage of a higher theoretical capacity of ~330 mAh/g, resulting from a reversible two electron redox process based on M2+/M3+ and M3+/M4+ redox couples with two extractable lithium ions per formula unit [21]. Due to the relatively higher stability of Mn4+ than Fe4+ and Co4+, Li2MnSiO4 could be the most promising candidate in the orthosilicate family [19]. However, there are still some issues that hamper the practical application of the Li2MnSiO4 compound as a cathode material. These include the intrinsic poor electronic conductivity and low ionic diffusivity of Li2MnSiO4, as well as the structural instability due to Jahn–Teller distortion. Various strategies have been applied to overcome these challenges. For example, the synthesis of nanomaterials with conductive coating has been examined [22], [23], [24].

Although a number of Li2MnSiO4-related nanomaterials has been synthesized, the phase purity and morphology have not been well-controlled for this system [19]. Most of the fabrication methods can be classified as wet chemistry-based reactions [25] or solid-state reactions [22]. Although wet-chemistry methods have been employed for the formation of a great variety of nanomaterials with tunable morphologies, it is challenging to derive Li2MnSiO4 by such approaches due to the possible presence of insoluble intermediate phases, including SiO2, Li2SiO3, MnO and Mn2SiO4. To achieve pure Li2MnSiO4, harsh conditions such as supercritical solvothermal processing with extremely high pressure are usually required [20], [24]. In conventional solid-state approaches, although the high reaction temperatures would result in improved phase purity and crystallinity, they would also lead to the collapse and aggregation/growth of nanostructures. Hence, the simultaneous control of morphology and phase purity of Li2MnSiO4 has not been achieved, and remains a major challenge.

Herein we employed a wet-chemistry associated solid-state reaction strategy for the synthesis of Li2MnSiO4-related nanomaterials (Figure 1), which would combine the advantages of wet-chemistry reaction methods and solid-state reaction approaches, while avoiding their disadvantages [26]. Firstly, monodispersed MnCO3 nanocubes were prepared through a water-in-oil (W/O) microemulsion process under ambient conditions. MnCO3@SiO2 core–shell nanocubes were then obtained via a modified Stöber silica coating recipe under mild wet-chemistry conditions [27]. After uniformly mixing MnCO3@SiO2 core–shell nanocubes with lithium acetate (LiAc) and lactose, calcination in an inert atmosphere at high temperature was performed. The MnCO3 cores would decompose into MnO and CO2 during the heating process [28]. The resulting MnO would further react with SiO2 and LiAc in the shells as templates to produce Li2MnSiO4 nanoboxes, and CO2 gas would be released to generate pores in the walls of the hollow structures. Meanwhile, a carbon coating would be formed in situ on the surface of Li2MnSiO4, resulting from the carbonization of lactose. Consequently, phase-pure Li2MnSiO4@C nanoboxes with a well-controlled porous and hollow architecture were successfully achieved for the first time. Combined with reduced graphene oxide (RGO) nanosheets, the as-prepared Li2MnSiO4@C/RGO nanocomposite performed as a promising high-capacity cathode candidate for Li-ion batteries.

Section snippets

Preparation of MnCO3 nanocubes suspension

The synthesis of MnCO3 nanocubes was modified from a previous report [29]. Typically, 2.0 g of cetyltrimethylammonium bromide (CTAB), 10 mmol of MnCl2·4H2O, 2.0 mL of water, 3.0 mL of 1-butanol and 60 mL of cyclohexane were mixed in container A. 8.0 g of CTAB, 19 mmol of KHCO3, 1.0 mmol of NH4HCO3, 2.0 mL of water, 3.0 mL of 1-butanol and 240 mL of cyclohexane were mixed in container B. After magnetic stirring at room temperature for 1 h, two water-in-oil microemulsions were formed. The feedstock in

Synthesis of phase-pure Li2MnSiO4@C porous nanoboxes

Since there were no impure residues after decomposition of MnCO3 as the manganese source for Li2MnSiO4, we selected MnCO3 nanomaterial as the initial template. Monodispersed MnCO3 nanoparticles could be readily prepared via a microemulsion-mediated solvothermal method by Wu and co-workers [29]. Unlike earlier report, we found that the uniform MnCO3 nanocubes could be obtained at room temperature without heating, and such processing would be much easier to scale up (see Experimental section for

Conclusions

In summary, phase-pure Li2MnSiO4@C nanoboxes with a well-crystalline porous wall have been successfully synthesized for the first time. Combined with RGO nanosheets, Li2MnSiO4@C/RGO nanocomposite was obtained as a promising high-capacity cathode material for Li-ion batteries. This study illustrated the simultaneous control of phase purity and nanoscale architecture, enabling Li2MnSiO4 nanomaterial to be achieved for the first time. The morphology of the MnCO3 nanocube template and the Si:Mn

Acknowledgments

This work was funded by the Institute of Bioengineering and Nanotechnology (Biomedical Research Council, Agency for Science, Technology and Research, Singapore) and the Hydro-Quebec Research Institute (Canada).

Xianfeng Yang received his Ph.D. from Sun Yat-Sen University in 2008, where he also spent two years as a Postdoctoral Research Fellow. He was a Research Associate with Prof. Jimmy C. Yu at the Chinese University of Hong Kong in 2008–2009. He was a Research Scientist in Prof. Jackie Y. Ying’s group at the Institute of Bioengineering and Nanotechnology in Singapore during 2010–2014. He is now a professor at South China University of Technology. His research interests include the development of

References (31)

  • J. Xu et al.

    Nano Energy

    (2013)
  • R.J. Gummow et al.

    J. Power Sources

    (2014)
  • R. Dominko et al.

    Electrochem. Commun.

    (2006)
  • H. Gong et al.

    J. Power Sources

    (2014)
  • M. Ohmori et al.

    J. Colloid Interface Sci.

    (1992)
  • B.L. Ellis et al.

    Chem. Mater.

    (2010)
  • Y.-K. Sun et al.

    Nat. Mater.

    (2012)
  • Z.P. Song et al.

    Energy Environ. Sci.

    (2013)
  • Y.S. Jung et al.

    Adv. Energy Mater.

    (2013)
  • I.D. Scott et al.

    Nano Lett.

    (2011)
  • W. Hu et al.

    ChemSusChem

    (2011)
  • M.A. Reddy et al.

    Adv. Energy Mater.

    (2013)
  • C.-P. Yang et al.

    Angew. Chem. Int. Ed.

    (2013)
  • A. Manthiram et al.

    Acc. Chem. Res.

    (2013)
  • Y. Yang et al.

    J. Am. Chem. Soc.

    (2012)
  • Cited by (34)

    • Advances in and prospects of nanomaterials’ morphological control for lithium rechargeable batteries

      2022, Nano Energy
      Citation Excerpt :

      With this intricate design, a stable capacity of ~150 mAh g-1 was shown at 1 C, with ~120 mAh g-1 retained at 10 C and stable cycling demonstrated. Similarly, we have also designed Li2MnSiO4 nanoboxes so as to balance the fast charge transport facilitated by the thin shells (~32 nm) with the higher tap density and stability of the sub-micrometer particles (Fig. 7b1–2) [76]. A high initial capacity of 335 mAh g-1 and a reversible capacity of ~220 mAh g-1 after 50 cycles were achieved.

    • Synergistic effect of LiF coating and carbon fiber electrode on enhanced electrochemical performance of Li<inf>2</inf>MnSiO<inf>4</inf>

      2021, Electrochimica Acta
      Citation Excerpt :

      But it has very low electronic conductivity (10−14 S cm−1), slow lithium-ion kinetics (10−16 cm2 s−1), and high amorphization during cycling which leads to complete failure of Li2MnSiO4 as cathode for Li-ion batteries [9–12]. Many efforts have been directed to improve the electronic and ionic conductivity by reducing the particle size which decreases the diffusion length, and through carbon coatings [11,13–28]. For example, Li et al. demonstrated for the first time that Li2MnSiO4/C nanocomposite could deliver a reversible capacity of 209 mAh g−1 (about 1.25 electrons transfer process) during the initial charge-discharge process [29].

    • Hollow structured cathode materials for rechargeable batteries

      2020, Science Bulletin
      Citation Excerpt :

      The relatively inferior performance of hydrothermal products was ascribed to unfavorable carbon coating compared with in-situ carbon coating generated by other techniques. Ying’s group [89] reported Li2MnSiO4@C hollow nanoboxes made from a wet-chemistry method followed by a solid-state reaction (Fig. 5d), during which hollow structure and carbon coating layered were in-situ formed. The composites were further modified by graphene oxide nanosheets, resulting in capacities of 290 and 220 mAh g−1 in the initial and 50th cycles at 0.02 C at 40 °C.

    View all citing articles on Scopus

    Xianfeng Yang received his Ph.D. from Sun Yat-Sen University in 2008, where he also spent two years as a Postdoctoral Research Fellow. He was a Research Associate with Prof. Jimmy C. Yu at the Chinese University of Hong Kong in 2008–2009. He was a Research Scientist in Prof. Jackie Y. Ying’s group at the Institute of Bioengineering and Nanotechnology in Singapore during 2010–2014. He is now a professor at South China University of Technology. His research interests include the development of nanomaterials for energy-related applications, and the relationship between microstructure and properties.

    Jinhua Yang received his Ph.D. in Chemical and Bimolecular Engineering from National University of Singapore in 2010. He is a Research Scientist at the Institute of Bioengineering and Nanotechnology. His research is focused on the synthesis and characterization of inorganic materials for electrochemical applications in fuel cells, batteries and supercapacitors.

    Karim Zaghib obtained his M.S. (1987) and Ph.D. (1990), both in electrochemistry, from the Institut National Polytechnique de Grenoble, France. In 2002, he received the HDR (Habilitation a Diriger la Recherche) in materials science from the Université de Pierre et Marie Curie, Paris, France. Dr. Zaghib was guest researcher for the Japanese Ministry of International Trade and Industry (1992–1995). He is currently the Director of the Conversion and Storage of Energy Department at Hydro-Québec. His research activities involve developing new battery technologies beyond Li-ion, such as solid state (Li–S, Li–air, Na, Mg, Ca) batteries. Dr. Zaghib has published 250 refereed papers and has 170 international patents. He has served as editor or co-editor of 17 books. He was organizer/co-organizer of 58 symposia, meetings and workshops. He was the General Chair of the International Meeting on Lithium Batteries (2010), and Organizer of the First International Conference on Olivines (2014). He served as the Chair of the Energy Technology Division (2007–2009), and was elected ECS Fellow (2011). Dr. Zaghib has received the International Electric Research Exchange Research Award (2008) in Brazil, the International Battery Association Research Award (2010), and the ECS Battery Technology Award (2013).

    Michel L. Trudeau has been working on the physical understanding and characterization of metastable and nanostructured materials. He started his career studying quantum transport properties at low temperature in metallic glasses, investigating magnetic transport and superconductivity. At Hydro-Quebec Research Institute (IREQ), he has investigated the structural and physical properties of a variety of metastable and nanostructured materials. He has worked on hydrogen electrocatalysis, photohydrolysis, fuel cells, electrical contacts, electrodeposition, high energy mechanical milling, hydrogen storage and batteries. He is the Group Leader of IREQ’s Materials Characterization Laboratory, which includes a Scanning Transmission Electron Microscope (STEM) with an information limit near 50 pm, and the first “cold-field emitter” Environmental TEM (300 kV). Dr. Trudeau has co-authored about 150 papers, which have been cited more than 3500 times, and has contributed to three patents. He has written four book chapters, and edited one volume of conference proceedings. He is a member of a number of international advisory committees. He has co-chaired six international meetings related to nanostructured materials, including the first Symposium on Nanocrystalline Solids at the American Physical Society (APS) Meeting in 1991. He is the Chair for the next International Conference on Nanostructured Materials in August 2016. He was elected Fellow of the APS for his work on nanostructured materials (2008).

    Jackie Y. Ying received her B.E. and Ph.D. from The Cooper Union and Princeton University, respectively. She joined the faculty at Massachusetts Institute of Technology in 1992, where she was Professor of Chemical Engineering until 2005. She has been the Founding Executive Director of the Institute of Bioengineering and Nanotechnology in Singapore since 2003. For her research on nanostructured materials, Prof. Ying has been recognized with the American Ceramic Society Ross C. Purdy Award, David and Lucile Packard Fellowship, Office of Naval Research Young Investigator Award, National Science Foundation Young Investigator Award, Camille Dreyfus Teacher-Scholar Award, American Chemical Society Faculty Fellowship Award in Solid-State Chemistry, Technology Review TR100 Young Innovator Award, American Institute of Chemical Engineers (AIChE) Allan P. Colburn Award, Singapore National Institute of Chemistry-BASF Award in Materials Chemistry, Wall Street Journal Asia Asian Innovation Silver Award, International Union of Biochemistry and Molecular Biology Jubilee Medal. Prof. Ying was elected a World Economic Forum Young Global Leader, a member of the German National Academy of Sciences, Leopoldina, a Fellow of the Materials Research Society, and a Fellow of the Royal Society of Chemistry (U.K.). She was named one of the “One Hundred Engineers of the Modern Era” by AIChE in its Centennial Celebration. She was an Inaugural Inductee for the Singapore Women’s Hall of Fame in 2014. She is the Editor-in-Chief of Nano Today.

    View full text