Ion Battery Anodes Research Articles

Direct bandgap emission from strain-doped germanium

Germanium (Ge) is an attractive material for Silicon (Si) compatible optoelectronics, but the nature of its indirect bandgap renders it an inefficient light emitter. Drawing inspiration from the significant expansion of Ge volume upon lithiation as a Lithium (Li) ion battery anode, here, we propose incorporating Li atoms into the Ge to cause lattice expansion to achieve the desired tensile strain for a transition from an indirect to a direct bandgap. Our first-principles calculations show that a minimal amount of 3 at.% Li can convert Ge from an indirect to a direct bandgap to possess a dipole transition matrix element comparable to that of typical direct bandgap semiconductors. To enhance compatibility with Si Complementary-Metal-Oxide-Semiconductors (CMOS) technology, we additionally suggest implanting noble gas atoms instead of Li atoms. We also demonstrate the tunability of the direct-bandgap emission wavelength through the manipulation of dopant concentration, enabling coverage of the mid-infrared to far-infrared spectrum. This Ge-based light-emitting approach presents exciting prospects for surpassing the physical limitations of Si technology in the field of photonics and calls for experimental proof-of-concept studies.

Excellent double metal MXenes MoWC anode: The synergistic effect of molybdenum and tungsten transition metal

Double transition metal MXenes are highly desirable as anodes in ion batteries due to their larger capacitance compared to traditional single transition metal MXenes. This study investigates the effect of W and Mo on the electrochemical properties of MoWC and MoWCO2 as anodes in sodium-ion batteries, using density functional theory calculations. It is found that due to the difference in electronegativity, the double transition metal phase collects more electrons at the metal terminal than the single metal phase. This additional charge is activated and transferred to the outside of the first adsorption layer, leading to an extra Na adsorption layer. Based on this mechanism, the capacities of MoWC and MoWCO2 are determined to be 204.10 and 165.54 mAhg−1, respectively, exceeding the theoretical capacities of single metal MXenes Mo2C and W2C. Furthermore, the Na diffusion barriers in the MoWC monolayer are higher than those in the single metal phase, but they are still competitive, with values of 0.072 eV on the Mo layer and 0.055 eV on the W layer. These findings offer valuable insights for future investigations of double transition metal MXenes as potential anodes in ion batteries.

Predict low energy structures of BSi monolayer as high-performance Li/Na/K ion battery anode

Silicon was regarded as a promising anode material for the next generation ion batteries due to the extremely high theoretical capacity (4200 mAh/g) and reasonable working potential. However, the dramatic volume change during the ion intercalation or deintercalation process as well as the poor electrical conductivity impedes its performance as an anode. Herein, we propose two dimensional (2D) puckered BSi anode to combine the advantages of silicon and boron-based materials. In this work, three novel 2D BSi monolayers are predicted: d1-BSi, c1-BSi, and c2-BSi, with d1-BSi, studied in detail as the anode of Li/Na/K ion batteries. The theoretical specific capacities are estimated at 1378, 1034, and 689 mAh/g for Li, Na, and K, respectively. The puckered structure benefits from its good rate capacity, with ion diffusion barriers along furrows at 0.37/0.24/0.14 eV for Li/Na/K. The averaged open circuit voltages (OCVs) are 0.53/0.53/0.87 V, respectively. The density of states and geometry optimization reveals that d1-BSi is a conductor during the intercalation of alkali metal atoms. Applying strain can decrease ion diffusion barriers efficiently for these ions. Our valuable results suggest that d1-BSi could be a promising anode candidate for Li/Na/K ion batteries.

Monolayer Ge2S: An auxetic semiconductor with high carrier mobility for metal (Na, K, Mg)-ion battery anodes

Using first-principles calculations, we propose a new two-dimensional Ge2S (space group P21212) with unique mechanical and electronic properties. Monolayer Ge2S has excellent thermal, mechanical, and dynamic stabilities, exhibiting a semiconducting behavior with an indirect bandgap and anisotropic carrier mobility. The uniaxial strain along the zigzag direction can induce an indirect-to-direct bandgap transition. Remarkably, Ge2S possesses large in-plane negative Poisson's ratios, comparable with that of well-known penta-graphene. Moreover, we identify Ge2S as a high-performance anode material for metal-ion batteries. It shows metallic features after adsorbing Na, K, and Mg, providing good electrical conductivity during the charge/discharge process. The diffusion of metal ions on Ge2S is anisotropic with modest energy barriers in the armchair direction of 0.12, 0.39, and 0.76 eV for Na, K, and Mg, respectively. Ge2S can adsorb metal atoms up to a stoichiometric ratio of 1:1, which yields storage capacities of 151.17, 151.17, and 302.35 mA h g−1 for Na, K, and Mg, respectively. The volume of Ge2S shrinks slightly upon the adsorption of metal ions even at high concentrations, ensuring a good cyclic stability. Besides, the average open circuit voltage (0.30–0.70 V) falls within the acceptable range (0.1–1.0 V) of the anode materials. These results make Ge2S a promising anode material for the design of future metal-ion batteries.

Hollow CoS/C Structures for High-Performance Li, Na, K Ion Batteries.

Alkali ion (Li, Na, and K) batteries as a new generation of energy storage devices are widely applied in portable electronic devices and large-scale energy storage equipment. The recent focus has been devoted to develop universal anodes for these alkali ion batteries with superior performance. Transition metal sulfides can accommodate alkaline ions with large radius to travel freely between layers due to its large interlayer spacing. Moreover, the composite with carbon material can further improve electrical conductivity of transition metal sulfides and reduce the electron transfer resistance, which is beneficial for the transport of alkali ions. Herein, we designed zeolitic imidazolate framework (ZIF)–derived hollow structures CoS/C for excellent alkali ion (Li, Na, and K) battery anodes. The porous carbon framework can improve the conductivity and effectively buffer the stress-induced structural damage. The ZIF-derived CoS/C anodes maintain a reversible capacity of 648.9, and 373.2, 224.8 mAh g−1 for Li, Na, and K ion batteries after 100 cycles, respectively. Its outstanding electrochemical performance is considered as a universal anode material for Li, Na, and K ion batteries.

Predict Low Energy Structures of Bsi Monolayer as High-Performance Li/Na/K Ion Battery Anode

Predict Low Energy Structures of Bsi Monolayer as High-Performance Li/Na/K Ion Battery Anode

Synthesis of NiSe2 Nanoparticles Embedded into Carbon Nanoplate as Lithium/Sodium Ion Battery Anodes

Synthesis of NiSe2 Nanoparticles Embedded into Carbon Nanoplate as Lithium/Sodium Ion Battery Anodes

Vacancy–vacancy pairs induced new phase formation in carbon boride: A design principle to achieve superior performance Li/Na‐ion battery anodes

AbstractDefect engineering is a desired manner to promote the performance of electrodes. Herein, by employing the boron atom substitution and carbon–boron vacancy–vacancy pairs in graphene, a defect‐induced two‐dimensional new phase, popC5B, is formed. The evidences indicate that it has dynamic, thermal, and mechanical stabilities. When used as anodes in Li/Na‐ion batteries, it possesses high theoretical specific capacities of 1891/1135 mAh/g. The high capacity is attributed to the synergy effect of various defect engineering and defect‐induced phase transition that lead to the charge delocalization in popC5B and promote the electron transfer between metal ions and popC5B. This study demonstrates that the synergy effect of various kinds of defects could be an effective approach to acquire high performance electrodes in batteries.image

Cover Feature: A Review on the Current Progress and Challenges of 2D Layered Transition Metal Dichalcogenides as Li/Na‐ion Battery Anodes (ChemElectroChem 13/2021)

The Cover Feature illustrates the advancement of the metal-ion battery (Li/Na-ion) using different transition metal dichalcogenides (TMDs) as anode material. Multi-electron transfer reaction and unique physico-chemical properties will be the highlight for TMDs as alternative anode material for future rechargeable battery. More information can be found in the Review by R. Sahoo et al.

A Review on the Current Progress and Challenges of 2D Layered Transition Metal Dichalcogenides as Li/Na‐ion Battery Anodes

AbstractEnergy storage systems play a crucial role to effectively utilize the recurrent renewable energy sources. In the last few decades, lithium‐ion battery (LIB) has emerged as the most convenient and viable energy storage systems and consequently, sodium‐ion battery (SIB) has drawn most of the attention of researchers as a potential alternative to LIB, especially in grid storage. Further development on LIB and SIB requires detection of novel electrode materials, precisely the anode. Captivating physico‐chemical properties and unique structure of layered transition metal dichalcogenides (TMDs) nanostructured materials have been rendered supremely appealing to the electrochemical energy conversion and storage devices researchers. In this review, synopsis of current state‐of‐art LIB and SIB anode materials, brief discussion on the different crystal structures and the common synthesis process of the TMDs have been articulated. Apart from these, detailed discussion on the electrochemical reaction and battery performance of different TMDs have been summarized and discussed in this review. The individuality of this review paper compared to the other reported review papers has also been highlighted in details. Finally, the challenges and limitations of the current TMDs materials, and outlook for the future improvement of TMDs in the energy sector have been proposed.

S, O dual-doped porous carbon derived from activation of waste papers as electrodes for high performance lithium ion capacitors.

To circumvent the imbalances of electrochemical kinetics and charge-storage capacity between Li+ ion battery anodes and capacitive cathodes in lithium-ion capacitors (LICs), dual carbon based LICs are constructed and investigated extensively. Herein, S, O dual-doped 3D net-like porous carbon (S-NPC) is prepared using waste paper as the carbon source through a facile solvothermal treatment and chemical activation. Benefiting from the combination effect of the rich S,O-doping (about 2.1 at% for S, and 9.0 at% for O), high surface area (2262 m2 g−1) and interconnected porous network structure, the S-NPC-40 material exhibits excellent electrochemical performance as both cathode material and anode material for LICs. S, O doping not only increases the pseudocapacity but also improves the electronic conductivity, which is beneficial to reduce the mismatch between the two electrodes. The S-NPC-40//S-NPC-40 LIC delivers high energy densities of 176.1 and 77.8 W h kg−1 at power densities of 400 and 20 kW kg−1, respectively, as well as superior cycling stability with 82% capacitance retention after 20 000 cycles at 2 A g−1. This research provides an efficient method to convert waste paper to porous carbon electrode materials for high performance LIC devices.

Monolayer Mo2B: A non-magnetic metal and potential application as anode material for ion batteries and catalyst for hydrogen evolution

Using the first principle method, the properties and electronic structures for two dimensional (2D) Mo2B are studied. Our investigations show 2D Mo2B with the hexagonal structure is a stable phase. Electronic structure show that 2D Mo2B is a typical metal and non-magnetic. The native defects, as well as a few percent of biaxial tensions and compressions cannot destroy its metallic behaviors. Stable metallic properties suggest 2D Mo2B is a promising electrode material in ion batteries. For Li and Na adsorbed cases, negative adsorption energies suggest strong interactions between Li (Na) and 2D Mo2B, which could prevent the formation of metallic Li and Na, and improve ions batteries’ safety and reversibility when utilized as anodes in ion batteries. The diffusion barriers for Li (Na) ions on 2D Mo2B are 0.073 (0.069) eV, and the open circuit voltage for Li (Na) adsorbed are 0.62–1.15 (0.42–1.41) V. Such diffusion barriers and open circuit voltage indicate 2D Mo2B is a promising anode material for Li or Na ion batteries. Smaller Gibbs free energy implies 2D Mo2B have a good prospect as a catalyst for hydrogen evolution.

Electrochemical performances of NiO/Ni2N nanocomposite thin film as anode material for lithium ion batteries

Despite the high specific capacities, the practical application of transition metal oxides as the lithium ion battery (LIB) anode is hindered by their low cycling stability, severe polarization, low initial coulombic efficiency, etc. Here, we report the synthesis of the NiO/Ni2N nanocomposite thin film by reactive magnetron sputtering with a Ni metal target in an atmosphere of 1 vol.% O2 and 99 vol.% N2. The existence of homogeneously dispersed nano Ni2N phase not only improves charge transfer kinetics, but also contributes to the one-off formation of a stable solid electrolyte interphase (SEI). In comparison with the NiO electrode, the NiO/Ni2N electrode exhibits significantly enhanced cycling stability with retention rate of 98.8% (85.6% for the NiO electrode) after 50 cycles, initial coulombic efficiency of 76.6% (65.0% for the NiO electrode) and rate capability with 515.3 mA·h·g−1 (340.1 mA·h·g−1 for the NiO electrode) at 1.6 A·g−1.

Template directed hydrothermal synthesis of flowerlike NiSex/C composites as lithium/sodium ion battery anodes

Transition metal selenides nanoparticles/carbon composites have been one of the promising lithium/sodium ion battery anodes. In the present study, NiSex nanoparticles encapsulated into microporous flowerlike carbon have been prepared by a hydrothermal route directed by the flowerlike Ni/C composite template. In a low hydrothermal temperature (i.e., 120 °C), the metallic Ni nanoparticles are transformed into Ni0.85Se, which has an average particle size of ~ 13.02 nm. The selenization degree and particle size can be obviously improved at a higher hydrothermal temperature (i.e., 160 or 180 °C), accompanying with the decrease in carbon content, and partial Ni0.85Se nanoparticles have been transformed into NiSe2. As anode of lithium ion batteries, the NiSex obtained at 180 °C (i.e., 180 °C-NiSe) can deliver a higher discharge capacity (e.g., 851.0 mA h g−1 after 100 cycles at 0.2 A g−1) and better cycling stability compared with the low temperature obtained sample. However, the rate capability and sodium ion storage performance of 120 °C-Ni0.85Se are better than the 180 °C-NiSex, and a discharge capacity of 326.5 mA h g−1 can be reached at a high rate of 5 A g−1 for 120 °C-Ni0.85Se. Also, a high capacity retention ratio of 64.3% after 100 cycles can be reached for 120 °C-Ni0.85Se as sodium ion battery anode. The different electrochemical performance can be attributed to the decreased particle size.

Ultrathin MoS2 nanosheets homogenously embedded in a N,O-codoped carbon matrix for high-performance lithium and sodium storage

Ultrathin MoS2 nanosheets uniformly embedded into a N,O-codoped carbon matrix possess outstanding cyclability and rate performances as a lithium/sodium ion battery anode.

Sp-sp2 Carbon Sheets as Promising Anode Materials for Na-Ion Batteries.

We explore the applicability of graphynes, two-dimensional carbon sheets with sp- and sp2-bonds, as sodium (Na)-ion battery anodes using first-principles density functional theory. We found that voltages attainable from the charging–discharging of Na into multilayer graphyne are proper for use as anodes. The composite is ∼C6Na2 at the maximum Na concentration, corresponding to gravimetric and volumetric capacities of ∼837 mAh g–1 and ∼1056 mAh cm–3, respectively. These are significantly greater than the corresponding values (372 mAh g–1 and 818 mAh cm–3) of graphite for lithium. We ascribe the enhancement of the capacities to their nanoporous structures with sp- and sp2-bonded carbon atoms, which effectively bind multiple Na atoms. We propose that sp–sp2 carbon sheets can be promising candidates for high-capacity Na-ion battery anodes.

Electrodeposition of Pure Phase Snsb As Anode Material for Lithium- and Sodium- Ion Batteries

Commercial industries currently utilize graphite as the primary lithium anode material for secondary batteries. Graphite’s gravimetric capacity, however, has already been fully utilized and materials with higher capacities are more desirable for the advancement of next generation applications, such as electric vehicles. Of these materials, intermetallic alloys such as SnSb are of interest due to their ability to store multiple alkali metals per metal center, resulting in higher gravimetric and volumetric capacities. Electrodeposition is a promising method to produce these alloy anodes, as it can control the particle morphology, size, thickness, composition, and is easily scalable to larger productions. In this work, we have successfully synthesized pure SnSb by electrodeposition which, based on the authors’ knowledge, is the first occurrence to date. The synthesis is carefully analyzed through tools and techniques such as cyclic voltammetry, scanning electron microscopy, and x-ray diffraction. Electrochemical testing of the electrodeposited SnSb samples showed promising performance of the material, with long cycle life and high rate capabilities as both lithium- and sodium- ion battery anodes. It is also found that purity of the material has an evident impact on the electrochemical performance of the electrode, in which control of the purity is important to the material’s cycling lifetime.

In-Situ STM Studies on Li- and Na- Intercalation Batteries

The processes of SEI formation and of intercalation are still not well understood on the molecular level. Scanning probe techniques are capable of analysing these processes under in-situ conditions. The SEI-formation on graphitic electrodes operated as an Li+-ion battery anode in a standard 1 M LiPF6 EC/DMC (1 : 1) electrolyte has been studied using in-situ electrochemical scanning tunnelling microscopy (EC-STM)1. Two different modes of in situ study were applied, one, which allowed to follow topographic and crystallographic changes (solvent co-intercalation, graphite exfoliation, SEI precipitation on the HOPG basal plane) of the graphite electrode during SEI-formation, and the second, which gave an insight into the SEI precipitation on the HOPG basal plane in real time. From the in situ EC-STM studies, not only conclusions about the SEI-topography could be drawn, but also about the formation mechanism and the chemical composition, which strongly depend on the electrode potential. It was shown that above 1.0 V vs. Li/Li+ the SEI-formation is still reversible, since the molecular structure of the solvent molecules remains intact during an initial reduction step. During further reduction, the molecular structures of the solvents are destructed, which causes irreversible charge losses. The reversible intercalation of solvated Na-ions into graphite and the concomitant formation of ternary Na-graphite intercalation compounds (GICs) is studied by EC-STM and other in-operando techniques2. Linear ethylene glycol dimethyl ether homologes (“glymes”) Gx with x+1 O-atoms were used as solvents, where x is 1-4. The intercalation mechanism of Na+(Gx)y-complexes was investigated with the focus on phase transitions and diffusion rates of the Na+(Gx)y-complexes inside the graphite lattice. For the four shortest glymes (G1 to G4), it is found by XRD that an intermediate stage 2 Na-GIC (NaC48) is formed upon partial sodiation of the graphite electrode. At full sodiation a stage 1 Na-GIC (NaC18, 112 mAh g-1) is obtained for G1, G2 and G4, while the G3-system is also forming a stage 1 Na-GIC but with less Na incorporated (NaC30, 70 mAh g-1). Phase transitions of a battery electrode upon ion-intercalation are visualised by STM on the atomic scale for the first time. In addition, local diffusion rates of the intercalated species inside the electrode were determined, a unique approach to determining kinetic effects in batteries on the atomic scale. The formation of a solid electrolyte interphase (SEI) is observed in EC-STM. Lukas Seidl, Sladjana Martens, Jiwei Ma, Ulrich Stimming, Oliver Schneider "In-Situ Scanning Tunneling Microscopy of the SEI Formation on Graphite Electrodes for Li-Ion Batteries" Nanoscale, 2016, 8, 14004;Seidl, N. Bucher, E. Chu, S. Hartung, S. Martens, O. Schneider and U. Stimming, "Intercalation of solvated Na-ions into graphite", Energy Environ. Sci.,2017, 10, 1631.

Hydrothermal synthesis and electrochemical performance of CuS@Sisal fiber carbon composite Lithium- ion battery anodes

Abstract The CuS@Sisal fiber carbon (CuS@SFC) composite was prepared and used as anode material for lithium-ion batteries(LIBs). CuS nanoparticles were homogeneously dispersed on the surfaces of SFC via a hydrothermal method. The electrochemical performance of CuS@SFC composite was investigated in comparison with pure SFC. The LIB with a CuS@SFC anode displays much better performances than those of pure SFC, with a initial discharge capacity up to 903 mAh/g and a reversible capacity of 303 mAh/g after 30 cycles at a current density of 50 mA/g. The enhanced electrochemical performance can be attributed to the synergistic action of CuS nanoparticles and SFC porous structures in the composite. These results indicate that CuS@SFC has promising prospects in LIBs applications.

Flexible ReS2 nanosheets/N-doped carbon nanofibers-based paper as a universal anode for alkali (Li, Na, K) ion battery

Alkali (Li, Na, K) ion battery have practically or potentially been widely used as a power source for portable electronic devices and electric vehicles. However, lack of universal anodes for these three alkali ion battery are restricting their development, especially for Na-ion battery and K-ion battery. Rhenium disulfide (ReS2), with large interlayer space and weak van der Waals interaction between layers, can afford massive alkali (lithium, sodium, and potassium) ions to diffuse easily between the layers. However, its low electronic conductivity and large volume changes in the conversion reaction significantly compromise the cycle life. To address this issue, here, we anchor ReS2 nanosheets onto nitrogen doped carbon nanofibers (N-CNF) which forms a flexible ReS2/N-CNFs paper for alkali (Li, Na, and K) ion battery anodes. The carbon nanofibers (CNFs) can improve the conductivity and the doped nitrogen can absorb sulfur and polysulfide generated by the conversion reaction. As a result, the ReS2/N-CNFs composite anode maintains a reversible capacity of 430 mAh/g after 400 cycles at 100mA/g in LIBs, 245mAh/g after 800 cycles at 100mA/g in NIBs, and 253 mAh/g after 100 cycles at 50mA/g in KIBs. This performance is one of the best among all ReS2 reported up to date. In addition, the solid electrolyte interface formation on ReS2 and the coulombic efficiency in different alkali ion batteries are also systemically investigated.