The low Coulombic efficiency of the lithium metal anode is recognized as the real bottleneck to practical high‐efficiency lithium metal batteries with limited Li excess. The grain size and ...microstructure of deposited lithium strongly influences the lithium plating/stripping efficiency. Here, a solubilizer‐mediated carbonate electrolyte that can realize grain coarsening of lithium deposits (>20 µm in width) with oriented columnar morphology, which is in sharp contrast with conventional nanoscale dendrite‐like lithium deposits in carbonate electrolytes, is reported. It exhibits improved Li Coulombic efficiency to 98.14% at a high capacity of 3 mAh cm−2 over 150 cycles, because the colossal lithium deposition with minimal tortuosity can maintain the bulk Li with continuous electron conducting pathway during the stripping process, thus enabling efficient Li utilization. Li/NMC811 full batteries, composed of thin Li anode (45 µm) and a high‐capacity NMC811 cathode (16.7 mg cm−2), can achieve at least 12 times longer lifespan (200 cycles).
A grain‐coarsening behavior of lithium deposits with oriented columnar morphology can be realized in a solubilizer‐mediated carbonate electrolyte. Nanowave‐structured solid electrolyte interphases derived from the Sn2+–NO3– coordination‐solvation structure promote a significant improvement in the lifespan (200 cycles) of Li/NMC811 full batteries (45 µm thin Li anode and 16.7 mg cm−2 NMC811 cathode).
The construction of lightweight, flexible and stretchable power systems for modern electronic devices without using elastic polymer substrates is critical but remains challenging. We have developed a ...new and general strategy to produce both freestanding, stretchable, and flexible supercapacitors and lithium‐ion batteries with remarkable electrochemical properties by designing novel carbon nanotube fiber springs as electrodes. These springlike electrodes can be stretched by over 300 %. In addition, the supercapacitors and lithium‐ion batteries have a flexible fiber shape that enables promising applications in electronic textiles.
My flexible friend: Springlike electrodes with remarkable electrochemical properties have been used to create flexible and stretchable fiber‐shaped supercapacitors and lithium‐ion batteries. The electrodes, which are made from twisted aligned multiwalled carbon nanotubes (see picture), can be stretched by over 300 %, and the devices show stable performance under bending and stretching deformations.
A stretchable Li4Ti5O12 anode and a LiFePO4 cathode with 80% stretchability are prepared using a 3D interconnected porous polydimethylsiloxane sponge based on sugar cubes. 82% and 91% capacity ...retention for anode and cathode are achieved after 500 stretch–release cycles. Slight capacity decay of 6% in the battery using the electrode in stretched state is observed.
Although lithium–sulfur (Li–S) batteries are one of the most promising energy storage devices owing to their high energy densities, the sluggish reaction kinetics and severe shuttle effect of the ...sulfur cathodes hinder their practical applications. Here, single atom zinc implanted MXene is introduced into a sulfur cathode, which can not only catalyze the conversion reactions of polysulfides by decreasing the energy barriers from Li2S4 to Li2S2/Li2S but also achieve strong interaction with polysulfides due to the high electronegativity of atomic zinc on MXene. Moreover, it is found that the homogenously dispersed zinc atoms can also accelerate the nucleation of Li2S2/Li2S on MXene layers during the redox reactions. As a result, the sulfur cathode with single atom zinc implanted MXene exhibits a high reversible capacity of 1136 mAh g−1. After electrode optimization, a high areal capacity of 5.3 mAh cm−2, high rate capability of 640 mAh g−1 at 6 C, and good cycle stability (80% capacity retention after 200 cycles at 4 C) can be achieved.
Single zinc atom implanted on MXene (Ti3C2Clx) layers not only possesses efficient electrocatalytic activity for polysulfides but also has a strong interaction with polysulfides owing to the high electronegativity of zinc atoms on MXene, greatly facilitating the nucleation and deposition of Li2S2/Li2S on MXene layers. Thus, a stable sulfur cathode with high areal capacity and high rate capabilities is achieved.
Hard carbon (non-graphitizable) and related materials, like tin, tin oxide, silicon, and silicon oxide, have a high theoretical lithium delivery capacity (>550 mAh/g depending on their structural and ...chemical properties) but unfortunately they also exhibit a large initial capacity loss (ICL) that overrides the true reversible capacity in a full cell. Overcoming the large ICL of hard carbon in a full-cell lithium-ion battery (LIB) necessitates a new strategy wherein a sacrificial lithium source additive, such as, Li5FeO4 (LFO), is inserted on the cathode side. Full batteries using hard carbon coupled with LFO-LiCoO2 (LCO) are currently under development at our laboratory. We find that the reversible capacity of a cathode containing LFO can be increased by 14%. Furthermore, the cycle performance of full cells with LFO additive is improved from <90% to >95%. We show that the LFO additive not only can address the irreversible capacity loss of the anode, but can also provide the additional lithium ion source required to mitigate the lithium loss caused by side reactions. In addition, we have explored the possibility to achieve higher capacity with hard carbon, whereby the energy density of full cells can be increased from ca. 300 Wh/kg to >400 Wh/kg.
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•Added Li5FeO4 in the cathode to mitigate the initial capacity loss of the anode.•Promoted the specific capacity and capacity retention of cathode simultaneously.•Improved the power and energy density of LIB simultaneously.
A vertically aligned carbon nanofiber (VACNF) array with unique conically stacked graphitic structure directly grown on a planar Cu current collector (denoted as VACNF/Cu) is used as a high‐porosity ...3D host to overcome the commonly encountered issues of Li metal anodes. The excellent electrical conductivity and highly active lithiophilic graphitic edge sites facilitate homogenous coaxial Li plating/stripping around each VACNF and forming a uniform solid electrolyte interphase. The high specific surface area effectively reduces the local current density and suppresses dendrite growth during the charging/discharging processes. Meanwhile, this open nanoscale vertical 3D structure eliminates the volume changes during Li plating/stripping. As a result, highly reversible Li plating/stripping with high coulombic efficiency is achieved at various current densities. A low voltage hysteresis of 35 mV over 500 h in symmetric cells is achieved at 1 mA cm−2 with an areal Li plating capacity of 2 mAh cm−2, which is far superior to the planar Cu current collector. Furthermore, a Li–S battery using a S@PAN cathode and a lithium‐plated VACNF/Cu (VACNF/Cu@Li) anode with slightly higher capacity (2 mAh cm−2) exhibits an excellent rate capability and high cycling stability with no capacity fading over 600 cycles.
A vertically aligned carbon nanofiber (VACNF) array is used for reversible Li plating/stripping and demonstrates high performance in Li–S batteries. Benefitting from the excellent electrical conductivity, high specific surface area, and the open 3D structure, the VACNF/Cu electrode can effectively facilitate coaxial Li deposition, suppress dendrite growth, and accommodate the volume change during Li plating/stripping.
As an integral part of all‐solid‐state lithium (Li) batteries (ASSLBs), solid‐state electrolytes (SSEs) must meet requirements in high ionic conductivity, electrochemical/chemical stability toward ...the electrode. The ionic conductivity of the Li super ionic conductor (LISICON) is limited, and the thio‐LISICON is improved by replacing O2− in the LISICON with S2−. Currently, the ionic conductivity of Li10GeP2S12 (LGPS) has exceeded 10 mS cm−1, which meets the demands of commercial ASSLBs. However, poor stability of SSEs, baneful interfacial reactions, Li dendrite growth, and other factors have impeded the development of ASSLBs. Hence, this review first traces the development progress of thio‐/LISICON and LGPS‐type SSEs, analyzes the complicated ion transport mechanism, and summarizes the effective strategies for improving ionic conductivity. Moreover, exciting methods focusing on electrode interface engineering are outlined separately. As to SSE/anode interface, poor chemical or electrochemical compatibility, poor interfacial contact, and the mechanisms of dendrite formation are discussed. For the SSE/cathode interface, poor interfacial stability and non‐intimate solid–solid contact are daunting challenges. Then, effective methods to improve interface stability and electrochemical performance of ASSLBs with LGPS‐type SSEs are introduced. Finally, combined with the present chances and challenges, the possible future developing directions of LGPS‐based ASSLBs and the perspectives are proposed.
The crystal structure and ionic transport mechanism of thio‐/lithium (Li) super ionic conductor and Li10GeP2S12 (LGPS)‐type solid electrolytes are discussed, and effective methods for improving ionic conductivity are summarized. The interface problem between electrode and electrolyte is analyzed in detail. LGPS‐type electrolytes have been successfully applied to all‐solid‐state lithium batteries and satisfactory energy density and power density are achieved.
Direct capture and storage of abundant but intermittent solar energy in electrical energy‐storage devices such as rechargeable lithium batteries is of great importance, and could provide a promising ...solution to the challenges of energy shortage and environment pollution. Here we report a new prototype of a solar‐driven chargeable lithium–sulfur (Li‐S) battery, in which the capture and storage of solar energy was realized by oxidizing S2− ions to polysulfide ions in aqueous solution with a Pt‐modified CdS photocatalyst. The battery can deliver a specific capacity of 792 mAh g−1 during 2 h photocharging process with a discharge potential of around 2.53 V versus Li+/Li. A specific capacity of 199 mAh g−1, reaching the level of conventional lithium‐ion batteries, can be achieved within 10 min photocharging. Moreover, the charging process of the battery can proceed under natural sunlight irradiation.
A solar‐driven chargeable Li‐S battery has been developed by introducing a Pt/CdS photocatalyst in the aqueous polysulfide cathode. The most remarkable feature of this designed device is the simultaneous realization of both large‐scale electrochemical storage and chemical fuel conversion of solar energy in one device, thus opening a new research area in pursuit of renewable clean energy.
The 2019 Nobel Prize in Chemistry for lithium‐ion batteries is a powerful confirmation of the importance of portable energy storage devices, which will further promote collaborative innovation in the ...field of new energy storage. Non‐lithium rechargeable energy storage technologies are attracting attention due to their low cost and high energy densities. However, electrochemical performance depends upon the inherent properties of the electrodes. In recent decades, 2D materials have been extensively investigated owing to their unique physical and chemical properties. One of the typical representatives is the MXenes with good electrochemical properties, which have become popular material in the field of energy storage in recent years. The discovery of MXene with metal solution, expanded interlayer‐spacing and tamperable surface termination offers a valuable strategy to discover MXenes with new structures. These flexible properties of MXene allow the tuning of properties for energy storage technologies. Here, the synthesis, structure, properties and applications of MXenes in non‐lithium energy storage technologies are reviewed, and a comprehensive outlook and personal perspective on the future development of MXene in the energy storage system are also presented.
This article summarizes the importance of MXene in the field of non‐lithium energy storage technologies. The preparation methods and structural properties of MXene are briefly presented, and the application of MXene based electrode materials in various non‐lithium energy storage systems is emphasized.
Solid‐state Li metal battery technology is attractive, owing to the high energy density, long lifespans, and better safety. A key obstacle in this technology is the unstable Li/solid‐state ...electrolyte (SSE) interface involving electrolyte reduction by Li. Herein we report a novel approach based on the use of a nanocomposite consisting of organic elastomeric salts (LiO‐(CH2O)n‐Li) and inorganic nanoparticle salts (LiF, ‐NSO2‐Li, Li2O), which serve as an interphase to protect Li10GeP2S12 (LGPS), a highly conductive but reducible SSE. The nanocomposite is formed in situ on Li via the electrochemical decomposition of a liquid electrolyte, thus having excellent chemical and electrochemical stability, affinity for Li and LGPS, and limited interfacial resistance. XPS depth profiling and SEM show that the nanocomposite effectively restrained the reduction of LGPS. Stable Li electrodeposition over 3000 h and a 200 cycle life for a full cell were achieved.
Incorporating a Li salt‐based nanocomposite interphase layer stabilizes the lithium metal/Li10GeP2S12 solid electrolyte interface. This layer consists of organic elastomeric salts and inorganic nanoparticle salts, which offer chemical stability and low resistance. Its use suppresses Li10GeP2S12 reduction and significantly enhanced stability of Li electrodeposition.
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