Suspension electrolyte with modified Li+ solvation environment for lithium metal batteries.
Designing a stable solid-electrolyte interphase on a Li anode is imperative to developing reliable Li metal batteries. Herein, we report a suspension electrolyte design that modifies the Li+ solvation environment in liquid electrolytes and creates inorganic-rich solid-electrolyte interphases on Li. Li2O nanoparticles suspended in liquid electrolytes were investigated as a proof of concept. Through theoretical and empirical analyses of Li2O suspension electrolytes, the roles played by Li2O in the liquid electrolyte and solid-electrolyte interphases of the Li anode are elucidated. Also, the suspension electrolyte design is applied in conventional and state-of-the-art high-performance electrolytes to demonstrate its applicability. Based on electrochemical analyses, improved Coulombic efficiency (up to ~99.7%), reduced Li nucleation overpotential, stabilized Li interphases and prolonged cycle life of anode-free cells (~70 cycles at 80% of initial capacity) were achieved with the suspension electrolytes. We expect this design principle and our findings to be expanded into developing electrolytes and solid-electrolyte interphases for Li metal batteries.
View details for DOI 10.1038/s41563-021-01172-3
View details for PubMedID 35039645
- Rational solvent molecule tuning for high-performance lithium metal battery electrolytes NATURE ENERGY 2022
Enabling reversible redox reactions in electrochemical cells using protected LiAl intermetallics as lithium metal anodes
2019; 5 (10)
View details for DOI 10.1126/sciadv.aax5587
- Langmuir-Blodgett artificial solid-electrolyte interphases for practical lithium metal batteries NATURE ENERGY 2018; 3 (10): 889–98
- Designing solid-electrolyte interphases for lithium sulfur electrodes using ionic shields NANO ENERGY 2017; 41: 573–82
- Multifunctional Separator Coatings for High-Performance Lithium-Sulfur Batteries ADVANCED MATERIALS INTERFACES 2016; 3 (22)
- Fabricating multifunctional nanoparticle membranes by a fast layer-by-layer Langmuir-Blodgett process: application in lithium-sulfur batteries JOURNAL OF MATERIALS CHEMISTRY A 2016; 4 (38): 14709–19
Templated 3D Ultrathin CVD Graphite Networks with Controllable Geometry: Synthesis and Application As Supercapacitor Electrodes
ACS APPLIED MATERIALS & INTERFACES
2014; 6 (21): 18413–17
Three-dimensional ultrathin graphitic foams are grown via chemical vapor deposition on templated Ni scaffolds, which are electrodeposited on a close-packed array of polystyrene microspheres. After removal of the Ni, free-standing foams composed of conjoined hollow ultrathin graphite spheres are obtained. Control over the pore size and foam thickness is demonstrated. The graphitic foam is tested as a supercapacitor electrode, exhibiting electrochemical double-layer capacitance values that compare well to those obtained with the state-of-the-art 3D graphene materials.
View details for DOI 10.1021/am504695t
View details for Web of Science ID 000344978200006
View details for PubMedID 25318008
- Flexible micro-supercapacitors with high energy density from simple transfer of photoresist-derived porous carbon electrodes CARBON 2014; 74: 163–69
FLEXIBLE MICRO-SUPERCAPACITORS FROM PHOTORESIST-DERIVED CARBON ELECTRODES ON FLEXIBLE SUBSTRATES
IEEE. 2014: 389–92
View details for Web of Science ID 000352217500101
Regulating electrodeposition morphology of lithium: towards commercially relevant secondary Li metal batteries.
Chemical Society reviews
Lithium, the lightest and most electronegative metallic element, has long been considered the ultimate choice as a battery anode for mobile, as well as in some stationary applications. The high electronegativity of Li is, however, a double-edged sword-it facilitates a large operating voltage when paired with essentially any cathode, promising a high cell-level energy density. It is also synonymous with a high chemical reactivity and low reduction potential. The interfaces a Li metal anode forms with any other material (liquid or solid) in an electrochemical cell are therefore always mediated by one or more products of its chemical or electrochemical reactions with that material. The physical, crystallographic, mechanical, electrochemical, and transport properties of the resultant new material phases (interphases) regulate all interfacial processes at a Li metal anode, including electrodeposition during battery recharge. This Review takes recent efforts aimed at manipulating the structure, composition, and physical properties of the solid electrolyte interphase (SEI) formed on an Li anode as a point of departure to discuss the structural, electrokinetic, and electrochemical requirements for achieving high anode reversibility. An important conclusion is that while recent reports showing significant advances in the achievement of highly reversible Li anodes, e.g. as measured by the coulombic efficiency (CE), raise prospects for as significant progress towards commercially relevant Li metal batteries, the plateauing of achievable CE values to around 99 ± 0.5% apparent from a comprehensive analysis of the literature is problematic because CE values of at least 99.7%, and preferably >99.9% are required for Li metal cells to live up to the potential for higher energy density batteries offered by the Li metal anode. On this basis, we discuss promising approaches for creating purpose-built interphases on Li, as well as for fabricating advanced Li electrode architectures for regulating Li electrodeposition morphology and crystallinity. Considering the large number of physical and chemical factors involved in achieving fine control of Li electrodeposition, we believe that achievement of the remaining 0.5% in anode reversibility will require fresh approaches, perhaps borrowed from other fields. We offer perspectives on both current and new strategies for achieving such Li anodes with the specific aim of engaging established contributors and newcomers to the field in the search for scalable solutions.
View details for DOI 10.1039/c9cs00883g
View details for PubMedID 32232259
- Facile and scalable fabrication of high-energy-density sulfur cathodes for pragmatic lithium-sulfur batteries JOURNAL OF POWER SOURCES 2019; 422: 104–12
Carbon Nitride Phosphorus as an Effective Lithium Polysulfide Adsorbent fro Lithium-Sulfur Batteries
ACS APPLIED MATERIALS & INTERFACES
2019; 11 (12): 11431–41
Lithium-sulfur (Li-S) batteries are attracting substantial attention because of their high-energy densities and potential applications in portable electronics. However, an intrinsic property of Li-S systems, that is, the solubility of lithium polysulfides (LiPSs), hinders the commercialization of Li-S batteries. Herein, a new material, that is, carbon nitride phosphorus (CNP), is designed and synthesized as a superior LiPS adsorbent to overcome the issues of Li-S batteries. Both the experimental results and the density functional theory (DFT) calculations confirm that CNP possesses the highest binding energy with LiPS at a P concentration of ∼22% (CNP22). The DFT calculations explain the simultaneous existence of Li-N bonding and P-S coordination in the sulfur cathode when CNP22 interacts with LiPS. By introducing CNP22 into the Li-S systems, a sufficient charging capacity at a low cutoff voltage, that is, 2.45 V, is effectively implemented, to minimize the side reactions, and therefore, to prolong the cycling life of Li-S systems. After 700 cycles, a Li-S cell with CNP22 gives a high discharge capacity of 850 mA h g-1 and a cycling stability with a decay rate of 0.041% cycle-1. The incorporation of CNP22 can achieve high performance in Li-S batteries without concerns regarding the LiPS shuttling phenomenon.
View details for DOI 10.1021/acsami.8b22249
View details for Web of Science ID 000462950600036
View details for PubMedID 30874419
- alpha-Fe2O3 anchored on porous N doped carbon derived from green microalgae via spray pyrolysis as anode materials for lithium ion batteries JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY 2019; 69: 39–47
- Stable Artificial Solid Electrolyte Interphases for Lithium Batteries CHEMISTRY OF MATERIALS 2017; 29 (10): 4181–89
Enhanced Li-S Batteries Using Amine-Functionalized Carbon Nanotubes in the Cathode
2016; 10 (1): 1050–59
The rechargeable lithium-sulfur (Li-S) battery is an attractive platform for high-energy, low-cost electrochemical energy storage. Practical Li-S cells are limited by several fundamental issues, including the low conductivity of sulfur and its reduction compounds with Li and the dissolution of long-chain lithium polysulfides (LiPS) into the electrolyte. We report on an approach that allows high-performance sulfur-carbon cathodes to be designed based on tethering polyethylenimine (PEI) polymers bearing large numbers of amine groups in every molecular unit to hydroxyl- and carboxyl-functionalized multiwall carbon nanotubes. Significantly, for the first time we show by means of direct dissolution kinetics measurements that the incorporation of CNT-PEI hybrids in a sulfur cathode stabilizes the cathode by both kinetic and thermodynamic processes. Composite sulfur cathodes based the CNT-PEI hybrids display high capacity at both low and high current rates, with capacity retention rates exceeding 90%. The attractive electrochemical performance of the materials is shown by means of DFT calculations and physical analysis to originate from three principal sources: (i) specific and strong interaction between sulfur species and amine groups in PEI; (ii) an interconnected conductive CNT substrate; and (iii) the combination of physical and thermal sequestration of LiPS provided by the CNT=PEI composite.
View details for DOI 10.1021/acsnano.5b06373
View details for Web of Science ID 000369115800114
View details for PubMedID 26634409
- Photoresist-derived porous carbon for on-chip micro-supercapacitors CARBON 2013; 57: 395–400
- Silicon carbide nanowires as highly robust electrodes for micro-supercapacitors JOURNAL OF POWER SOURCES 2013; 230: 298–302
- Cycling characteristics of high energy density, electrochemically activated porous-carbon supercapacitor electrodes in aqueous electrolytes JOURNAL OF MATERIALS CHEMISTRY A 2013; 1 (35): 10518–23