Sodium‐ion batteries, with their evident superiority in resource abundance and cost, are emerging as promising next‐generation energy storage systems for large‐scale applications, such as smart grids ...and low‐speed electric vehicles. Accidents related to fires and explosions for batteries are a reminder that safety is prerequisite for energy storage systems, especially when aiming for grid‐scale use. In a typical electrochemical secondary battery, the electrical power is stored and released via processes that generate thermal energy, leading to temperature increments in the battery system, which is the main cause for battery thermal abuse. The investigation of the energy generated during the chemical/electrochemical reactions is of paramount importance for battery safety, unfortunately, it has not received the attention it deserves. In this review, the fundamentals of the heat generation, accumulation, and transportation in a battery system are summarized and recent key research on materials design to improve sodium‐ion battery safety is highlighted. Several effective materials design concepts are also discussed. This review is designed to arouse the attention of researcher and scholars and inspire further improvements in battery safety.
This review summarizes the major heat generation sources, the electrochemical/chemical reactions that occur during thermal runaway processes, and recent progress in materials design for high safety sodium‐ion batteries. Minimizing irreversible heat Qp and side reaction heat Qs, accelerating the heat transport rate, and flame retardants would be effective directions to prevent fire or explosion accidents.
A safe, rechargeable potassium battery of high energy density and excellent cycling stability has been developed. The anion component of the electrolyte salt is inserted into a polyaniline cathode ...upon charging and extracted from it during discharging while the K+ ion of the KPF6 salt is plated/stripped on the potassium‐metal anode. The use of a p‐type polymer cathode increases the cell voltage. By replacing the organic‐liquid electrolyte in a glass‐fiber separator with a polymer‐gel electrolyte of cross‐linked poly(methyl methacrylate), a dendrite‐free potassium anode can be plated/stripped, and the electrode/electrolyte interface is stabilized. The potassium anode wets the polymer, and the cross‐linked architecture provides small pores of adjustable sizes to stabilize a solid‐electrolyte interphase formed at the anode/electrolyte interface. This alternative electrolyte/cathode strategy offers a promising new approach to low‐cost potassium batteries for the stationary storage of electric power.
A safe potassium battery with a high energy density and good cycling stability is based on a p‐type organic polyaniline cathode and a cross‐linked polymer‐gel electrolyte. The polyaniline cathode is a host for the insertion/extraction of the anion component of the electrolyte KPF6 salt while the polymer‐gel electrolyte allows dendrite‐free plating of a metallic potassium anode.
As one of the fascinating high capacity cathodes, O3‐type layered oxides usually suffer from their intrinsic air sensitivity and sluggish kinetics originating from the spontaneous lattice Na ...extraction during air exposure and high tetrahedral site energy of Na+ diffusion transition state. What is worse, the improvement on the two handicaps is hard to simultaneously realize because of the contradiction between Na containment suggested in air stability mechanism and enhanced Na diffusion mentioned in kinetics strategy. Herein, it is shown that a simple strategy of introducing proper Na vacancies into lattice can simultaneously realize a dual performance improvement. Na vacancies decrease the charge density on transitional metal ions and enhance the antioxidative capability of material, ensuring a stable lattice Na containment for Na0.93Li0.12Ni0.25Fe0.15Mn0.48O2 when exposed to air. Additionally, more Na+ diffusional sites and enlarged Na layer spacing are obtained and result in a significantly decreased energy barrier from ≈1000 to 300 meV and a high rate capability of 70.8% retention at 2000 mA g−1. Remarkably, such a strategy can be easily realized by either pre‐ or post‐treating, which exhibits excellent universality for various O3 materials, implying its enormous potential to promote the commercial application of O3‐type cathodes.
A universal strategy of introducing proper Na vacancies into a crystal lattice is proposed to simultaneously improve air‐stability and kinetics of O3‐type layered oxide cathodes. The dual improvement benefits from the multiple effects of Na vacancies on crystalline and electronic structure, namely, decreased charge density on transition metal ions, enhanced antioxidative capability, decreased Na+ diffusion barrier, and optimized migration path.
No single polymer or liquid electrolyte has a large enough energy gap between the empty and occupied electronic states for both dendrite‐free plating of a lithium‐metal anode and a Li+ extraction ...from an oxide host cathode without electrolyte oxidation in a high‐voltage cell during the charge process. Therefore, a double‐layer polymer electrolyte is investigated, in which one polymer provides dendrite‐free plating of a Li‐metal anode and the other allows a Li+ extraction from an oxide host cathode without oxidation of the electrolyte in a 4 V cell over a stable charge/discharge cycling at 65 °C; a poly(ethylene oxide) polymer contacts the lithium‐metal anode and a poly(N‐methyl‐malonic amide) contacts the cathode. All interfaces of the flexible, plastic electrolyte remain stable with no visible reduction of the Li+ conductivity on crossing the polymer/polymer interface.
A double‐layer polymer electrolyte is prepared for all‐solid‐state high‐voltage batteries, in which one polymer provides dendrite‐free lithium plating and the other allows Li+ extraction from a high‐voltage cathode without oxidation of the electrolyte, which exhibits good cycling stability in all‐solid‐state Li/LiCoO2 cells.
SiOx is proposed as one of the most promising anodes for Li‐ion batteries (LIBs) for its advantageous capacity and stable Li uptake/release electrochemistry, yet its practical application is still a ...big challenge. Here encapsulation of SiOx nanoparticles into conductive graphene bubble film via a facile and scalable self‐assembly in solution is shown. The SiOx nanoparticles are closely wrapped in multilayered graphene to reconstruct a flake‐graphite‐like macrostructure, which promises uniform and agglomeration‐free distribution of SiOx in the carbon while ensures a high mechanical strength and a high tap density of the composite. The composites present unprecedented cycling stability and excellent rate capabilities upon Li storage, rendering an opportunity for its anode use in the next‐generation high‐energy LIBs.
SiOx nanoparticles are closely wrapped in multilayered graphene to reconstruct a macrostructure resembling flake graphite, which promises agglomeration‐free distribution of SiOx in the bulk while ensuring a high mechanical strength and a high tap density of the bubble film. By taking the advantages of the graphene network, the composites present unprecedented cycling stability and excellent rate capabilities upon Li storage.
The demand to increase energy density of rechargeable batteries for portable electronic devices and electric vehicles and to reduce the cost for grid‐scale energy storage necessitates the exploration ...of new chemistries of electrode materials for rechargeable batteries. The open framework‐structure of Prussian‐blue materials has recently been demonstrated as a promising cathode host for a variety of monovalent and multivalent cations with the tunable working voltage and discharge capacities. Recent progress toward the application of Prussian‐blue cathode materials for rechargeable batteries is reviewed, with special emphasis on charge‐storage mechanisms of different insertion species, factors influencing electrochemical performances, and possible approaches to overcome their intrinsic limitations.
An in‐depth understanding of the chemistry of Prussian blue materials for rechargeable batteries, including monovalent ion and multivalent ion batteries, has been provided in this review, with special focus on emerging battery systems of multivalent ion batteries. The electrochemical performance and charge storage mechanism of the Prussian blue electrode materials with respect to the different battery systems were compared and discussed.
Rechargeable aqueous zinc‐ion batteries are considered as ideal candidates for large‐scale energy storage due to their high safety, eco‐friendliness, and low cost. However, Zn anode invites dendrite ...growth and parasitic reactions at anode‐electrolyte interface, impeding the practical realization of the battery. In this study, the electrochemical performance of the Zn‐metal anode is proposed to improve by using a 3D ZnTe semiconductor substrate. The substrate features high zincophilicity, high electronic conductivity and electron affinity, and a low Zn nucleation energy barrier to promote dendrite‐proof Zn deposition along the (002) crystal plane, while it also maintains high chemical stability against parasitic metal corrosion and hydrogen evolution reactions at surface, and a stable skeleton structure against the volume variation of anode. A Zn‐metal anode based on the telluride substrate shows a long cycle life of over 3300 h with a small voltage hysteresis of 48 and 320 mV at 1 and 30 mA cm−2, respectively. A zinc telluride@Zn//MnO2 full cell can operate for over 500 cycles under practical conditions in terms of lean electrolyte (18 µL mAh−1) and limited Zn metal ( negative/positive capacity ratio of 3:1, and a high mass loading of the cathode.
Dendrite growth and parasitic side reactions at anode‐electrolyte interface severely impede the practical realization of aqueous zinc ion batteries. Herein, a zincophilic artificial layer of 3D‐interconnected ZnTe layer on the Zn matrix to develop high‐reversibility Zn anode with dendrite‐proof Zn deposition along the (002) crystal plane and suppressed side reactions is reported.
Room‐Temperature Liquid Na–K Anode Membranes Xue, Leigang; Zhou, Weidong; Xin, Sen ...
Angewandte Chemie (International ed.),
October 22, 2018, Letnik:
57, Številka:
43
Journal Article
Recenzirano
Odprti dostop
The Na–K alloy is a liquid at 25 °C over a large compositional range. The liquid alloy is also immiscible in the organic‐liquid electrolytes of an alkali‐ion rechargeable battery, providing ...dendrite‐free liquid alkali‐metal batteries with a liquid–liquid anode‐electrolyte interface at room temperature. The two liquids are each immobilized in a porous matrix. In previous work, the porous matrix used to immobilize the alloy was a carbon paper that is wet by the alloy at 420 °C; the alloy remains in the paper at room temperature. Here we report a room‐temperature vacuum infiltration of the alloy into a porous Cu or Al membrane and a reversible stripping/plating of the liquid alloy with the immobilized organic‐liquid electrolyte; no self‐diacharge is observed since the liquid Na–K does not dissolve into the liquid carbonate electrolytes. The preparation and stripping/plating of the liquid alkali‐metal anode can both now be done safely at room temperature.
As an alternative to the high‐temperature Na–S battery with a dendrite‐free molten sodium anode, a room‐temperature liquid alkali‐metal battery with a liquid Na‐K anode and a liquid organic electrolyte is proposed. The liquid Na–K anode membranes can be prepared, used, and recycled at room temperature.
Li7La3Zr2O12‐based Li‐rich garnets react with water and carbon dioxide in air to form a Li‐ion insulating Li2CO3 layer on the surface of the garnet particles, which results in a large interfacial ...resistance for Li‐ion transfer. Here, we introduce LiF to garnet Li6.5La3Zr1.5Ta0.5O12 (LLZT) to increase the stability of the garnet electrolyte against moist air; the garnet LLZT‐2 wt % LiF (LLZT‐2LiF) has less Li2CO3 on the surface and shows a small interfacial resistance with Li metal, a solid polymer electrolyte, and organic‐liquid electrolytes. An all‐solid‐state Li/polymer/LLZT‐2LiF/LiFePO4 battery has a high Coulombic efficiency and long cycle life; a Li‐S cell with the LLZT‐2LiF electrolyte as a separator, which blocks the polysulfide transport towards the Li‐metal, also has high Coulombic efficiency and kept 93 % of its capacity after 100 cycles.
A LiF‐modified garnet, LLZT‐2LiF, has less Li2CO3 on the surface than the untreated compound and shows a small interfacial resistance with Li metal, a solid polymer electrolyte, and organic‐liquid electrolytes. An all‐solid‐state Li/polymer/LLZT‐2LiF/LiFePO4 battery has a high Coulombic efficiency and long cycle life.
Abstract
Na-ion cathode materials operating at high voltage with a stable cycling behavior are needed to develop future high-energy Na-ion cells. However, the irreversible oxygen redox reaction at ...the high-voltage region in sodium layered cathode materials generates structural instability and poor capacity retention upon cycling. Here, we report a doping strategy by incorporating light-weight boron into the cathode active material lattice to decrease the irreversible oxygen oxidation at high voltages (i.e., >4.0 V vs. Na
+
/Na). The presence of covalent B–O bonds and the negative charges of the oxygen atoms ensures a robust ligand framework for the NaLi
1/9
Ni
2/9
Fe
2/9
Mn
4/9
O
2
cathode material while mitigating the excessive oxidation of oxygen for charge compensation and avoiding irreversible structural changes during cell operation. The B-doped cathode material promotes reversible transition metal redox reaction enabling a room-temperature capacity of 160.5 mAh g
−1
at 25 mA g
−1
and capacity retention of 82.8% after 200 cycles at 250 mA g
−1
. A 71.28 mAh single-coated lab-scale Na-ion pouch cell comprising a pre-sodiated hard carbon-based anode and B-doped cathode material is also reported as proof of concept.
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