Toward Practical High-Energy and High-Power Lithium Battery Anodes: Present and Future

Abstract

Lithium batteries are key components of portable devices and electric vehicles due to their high energy density and long cycle life. To meet the increasing requirements of electric devices, however, energy density of Li batteries needs to be further improved. Anode materials, as a key component of the Li batteries, have a remarkable effect on the increase of the overall energy density. At present, various anode materials including Li anodes, high-capacity alloy-type anode materials, phosphorus-based anodes, and silicon anodes have shown great potential for Li batteries. Composite-structure anode materials will be further developed to cater to the growing demands for electrochemical storage devices with high-energy-density and high-power-density. In this review, the latest progress in the development of high-energy Li batteries focusing on high-energy-capacity anode materials has been summarized in detail. In addition, the challenges for the rational design of current Li battery anodes and the future trends are also presented.

Keywords: Li anodes; Li batteries; P anodes; Si anodes; high energy.

Figure 1

Ideal Li battery anodes for achieving high gravimetric energy densities. Images clockwise starting from the top image: Reproduced with permission.^{[ 31 ]} Copyright 2019, Springer Nature. Reproduced with permission.^{[ 28 ]} Copyright 2017, AAAS. Reproduced with permission.^{[ 36 ]} Copyright 2017, American Chemical Society. Reproduced with permission.^{[ 36 ]} Copyright 2017, American Chemical Society. Reproduced with permission.^{[ 33 ]} Copyright 2020, Elsevier. Reproduced with permission.^{[ 34 ]} Copyright 2013, American Chemical Society. Reproduced with permission.^{[ 35 ]} Copyright 2019, Elsevier. Reproduced with permission.^{[ 32 ]} Copyright 2018, National Academy of Sciences. Reproduced with permission.^{[ 25 ]} Copyright 2010, American Chemical Society. Reproduced with permission.^{[ 29 ]} Copyright 2019, The Royal Society of Chemistry. Reproduced with permission.^{[ 26 ]} Copyright 2012, American Chemical Society. Reproduced with permission.^{[ 27 ]} Copyright 2016, American Chemical Society. Reproduced with permission.^{[ 30 ]} Copyright 2014, Springer Nature.

Figure 2

a) Electrode pulverization of Si. b) Schematic of porous Si anode. Reproduced with permission.^{[ 31 ]} Copyright 2019, Nature Publishing Group. c) SEM image of the Si nanotubes, inset the TEM image indicates the hollow nature of the sample. Reproduced with permission.^{[ 47 ]} Copyright 2012, Nature Publishing Group. d) Schematic illustration and cross‐sectional SEM images of Si array. Reproduced with permission.^{[ 48 ]} Copyright 2010, American Chemical Society. e) Schematic and AFM images of Si nanosheets. Reproduced with permission.^{[ 49 ]} Copyright 2016, American Chemical Society. f) Schematic and SEM image of hollow Si nanospheres. Reproduced with permission.^{[ 50 ]} Copyright 2011, American Chemical Society.

Figure 3

a) A magnified schematic and TEM images of Si@void@C particles, and its delithiation capacity and CE of the first 1000 galvanostatic cycles. Reproduced with permission.^{[ 55 ]} Copyright 2012, American Chemical Society. b) Schematic illustration showing the structural maintenance of the Si@a‐TiO₂ nanoparticle electrode during lithium insertion and extraction. Reproduced with permission.^{[ 45 ]} Copyright 2017, Wiley‐VCH. c) Schematic and cycling performance of SiO _x @G, together with its atomic percentage of F in different anodes after 1000 cycles. Reproduced with permission.^{[ 58 ]} Copyright 2018, Wiley‐VCH. d) Graphical representation of the operation of PR‐PAA binder to dissipate the stress during repeated volume changes of SiMPs. Reproduced with permission.^{[ 28 ]} Copyright 2017, American Association for the Advancement of Science.

Figure 4

a) Schematic illustration of hollow nanospheres with porous shells during lithiation/sodiation and volume variation. Reproduced with permission.^{[ 72 ]} Copyright 2017, Wiley‐VCH. b) HRTEM image and schematic of BP‐G composite, together with the charge–discharge profiles of red P, BP/G, and BP‐G electrodes at the first cycle. Reproduced with permission.^{[ 76 ]} Copyright 2014, American Chemical Society. c) Schematic and cycling performance of SiO _x @G, together with its atomic percentage of F in different anodes after 1000 cycles. Reproduced with permission.^{[ 77 ]} Copyright 2016, Wiley‐VCH. d) Schematic of Li surface loading (adsorption process), diffusion along armchair and zigzag directions on phosphorene surface. Reproduced with permission.^{[ 78 ]} Copyright 2015, American Chemical Society. e) Schematic of (BP‐G)/PANI, and BP‐G hybrid structure with in plane P–C bonds. Reproduced with permission.^{[ 79 ]} Copyright 2020, American Association for the Advancement of Science.

Figure 5

a) Dilemmas of Li‐metal Anodes. Reproduced with permission.^{[ 80 ]} Copyright 2017, American Chemical Society. b) Schematic illustration showing the morphology difference of lithium deposited on the stainless, with or without the polysulfide and LiNO₃. Reproduced with permission.^{[ 87 ]} Copyright 2015, Nature Publishing Group. c) Illustration of the proposed electrochemical deposition processes of Li metal on 3D current collector. Reproduced with permission.^{[ 93 ]} Copyright 2015, Nature Publishing Group. d) Electrode volume change rate of MOF‐HCF@Li anode after plating, inset the schematic illustration of the Li plating/stripping process. Reproduced with permission.^{[ 35 ]} Copyright 2019, Elsevier. e) Schematic for the process of Li deposited in the 3D ion‐conductive host from the bottom current collector. Reproduced with permission.^{[ 32 ]} Copyright 2018, National Academy of Sciences. f) Schematics illustrating the fabrication process of the 3D Li anode with flowable interphase for solid‐state Li battery. Reproduced with permission.^{[ 105 ]} Copyright 2017, American Association for the Advancement of Science.

Figure 6

a) Schematic illustration of the hierarchical porous interconnected Si@N, O‐dual‐doped carbon. Reproduced with permission.^{[ 113 ]} Copyright 2017, Elsevier. b) Volume expansion curve of the particle recorded during the lithiation process, inset the schematic figure of CNT@Si@C microspheres. Reproduced with permission.^{[ 111 ]} Copyright 2020, Nature Publishing Group. c) Schematic diagrams showing the Li plating process on the CMN, and morphological evolution of Li plating on the CMN. Reproduced with permission.^{[ 36 ]} Copyright 2017, American Chemical Society. d) Schematic illustrating the thickness of the cell stack for anode‐free lithium metal, conventional lithium‐ion, and hybrid lithium‐ion/lithium metal cells based on the electrode loadings from the pouch cells. Reproduced with permission.^{[ 33 ]} Copyright 2020, Elsevier.