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Aqueous Li-ion batteries (ALIBs) are regarded as promising large-scale energy storage technology because of their intrinsic safety and cost-effectiveness. However, because of the “cathodic challenge” encountered using aqueous electrolytes, the choice of anode material is restricted to candidates having relatively high redox potential and low capacity, thus resulting in low energy density. In this communication, we report a TiO2 B anode for ALIBs that has low lithiation potential (∼1.6 V in nonaqueous electrolytes and ∼1.8 V in aqueous electrolytes), high capacity (∼200 mAh/g), and high structural stability. When the TiO2 B anode is paired with spinel LiMn2O4, the LiMn2O4//TiO2 B full cell can deliver high capacity (194.5 mAh/g, based on the anode mass) and high energy density (150 Wh/kg, based on the total electrode mass). Furthermore, a full cell employing this anode displays superior cycling performance with a high capacity retention of 76% after 400 cycles at 1 C, this is attributed to the structural stability of the TiO2 B nanowires and the wide electrochemical stability window of the Water-in-Salt (WIS) electrolyte. It is anticipated that the TiO2 B anode can provide a new option for constructing high-energy ALIBs.

Cobalt-free LiNiO2 cathode materials offer a higher energy density at a lower cost than high Co-containing cathode materials. However, Ni(OH)2 precursors for LiNiO2 cathodes are traditionally prepared by the coprecipitation method, which is expensive, complex, and time-consuming. Herein, we report a fast, facile, and inexpensive electrolysis process to prepare a Ni(OH)2 precursor, which was mixed with LiOH/LiNO3 salts to obtain a LiNiO2 cathode material. A combination of advanced characterization techniques revealed that the LiNiO2 cathode material prepared in this way exhibited an excellent layered structure with negligible Li/Ni site mixing and surface structural distortion. Electrochemical cycling of the LiNiO2 cathode material showed an initial discharge capacity of 235.2 mA h/g and a capacity retention of 80.2% after 100 cycles (at 1 C) between 2.75 and 4.3 V. The degradation of the cycling performance of the LiNiO2 cathode material was mainly attributed to the formation of a surface solid-electrolyte interface and a ∼5 nm rock salt-like structure, while the bulk structure of the cathode after cycling was generally stable.

Super-concentrated water-in-salt electrolytes make high-voltage aqueous batteries possible, but at the expense of high cost and several adverse effects, including high viscosity, low conductivity and slow kinetics. Here, we observe a concentration-dependent association between CO2 and TFSI anions in water that reaches maximum strength at 5 mol kg−1 LiTFSI. This TFSI–CO2 complex and its reduction chemistry allow us to decouple the interphasial responsibility of an aqueous electrolyte from its bulk properties, hence making high-voltage aqueous Li-ion batteries practical in dilute salt-in-water electrolytes. The CO2/salt-in-water electrolyte not only inherits the wide electrochemical stability window and non-flammability from water-in-salt electrolytes but also successfully circumvents the numerous disadvantages induced by excessive salt. This work represents a deviation from the water-in-salt pathway that not only benefits the development of practical aqueous batteries, but also highlights how the complex interactions between electrolyte components can be used to manipulate interphasial chemistry. Super-concentrated water-in-salt electrolytes enable high-voltage aqueous batteries, but have considerable drawbacks such as high viscosity, low conductivity and slow kinetics. Now a concentration-dependent association between CO2 and TFSI– has been discovered and leveraged to decouple the interphasial responsibility of an aqueous electrolyte from its bulk properties, making high-voltage aqueous Li-ion batteries practical in dilute salt-in-water electrolytes.

Inorganic solid-state electrolytes (ISSEs) have been extensively researched as the critical component in all-solid-state lithium-metal batteries (ASSLMBs). Many ISSEs exhibit high ionic conductivities up to 10

The reactivity of garnet solid electrolytes toward humid air hinders their practical application despite their attractive, superior properties such as high Li+ conductivity and wide electrochemical window. Sealing garnets with organic solvents can not only prevent them from reacting with humid air but also render them compatible with other processing technologies. Therefore, the chemical and structural stability of garnets in organic solvents must be studied. In this study, we selected several commonly used organic solvents with different representative functional groups to investigate their stability with garnets and reaction mechanisms. The experiments and theoretical calculations revealed that all of the solvents reacted with garnets through Li-H exchange, and solvent acidity determined the reaction strength. Furthermore, the solvent acidity was closely correlated to the functional groups connected to H atoms, which can affect charge distribution. Solvents or the tautomer of the solvents with hydroxyl groups such as alcohol, acetone, and N-methyl pyrrolidone, which are relatively more acidic, can lead to a violent reaction with changes in the lattice parameters of garnets. Ether compounds and saturated aliphatic hydrocarbons with relatively low acidity are highly stable against garnets. The proposed reaction mechanisms and rules may help in selecting appropriate solvents for different applications of garnets.

Rechargeable lithium-based batteries built with high-energy anode materials (e.g., silicon-based and silicon-derivative materials) are considered a feasible solution to satisfy the stringent requirements imposed by emerging markets, including electric vehicles and grid storage, due to their higher energy density compared to contemporary lithium-ion batteries. The robustness of the solid electrolyte interphase (SEI) layer on high-energy anodes is critical to achieve long-term and stable cycling performances of the batteries. Herein, we propose a new type of designer cathode additive (DCA), i.e., an ultrathin coating layer of elemental sulfur on the cathode, for the in situ formation of a thin and robust SEI layer on various types of high-energy anodes. The DCA elemental sulfur undergoes simultaneous oxidation and reduction paths, forming lithium alkyl sulfate (R-OSO

The increasing demand for high-energy powers have greatly incentivized the development of lithium carbon fluoride (Li||CF

The lack of appropriate cathodes is restraining the advances of Mg batteries. Crystalline cathode materials suffer from sluggish reaction kinetics and low-capacity delivery. The finite type of crystalline structure further confines the rational design of cathode materials. Herein, we proposed amorphization and anion enrichment as a brand-new strategy to not only enhance the solid-state ion diffusion and provide more ion-storage sites in amorphous structure but also contribute to the local transfer of multiple electrons through the additional anionic redox centers. Accordingly, a series of amorphous titanium polysulfides (a-TiS x , x = 2, 3, and 4) were designed, which significantly outperformed their crystalline counterparts and achieved a highly competitive energy density of ∼260 Wh/kg. The unique Mg2+ storage mechanism involves the dissociation/formation of S-S bonds and changes in the coordination number of Ti, namely, a mixture of conversion and intercalation reaction, accompanied by the joint cationic (Ti) and anionic (S) redox-rich chemistry. Our proposed amorphous and redox-rich design philosophy might provide an innovative direction for developing high-performance cathode materials for multivalent-ion batteries.

Anode-free lithium metal batteries can maximize the energy density at the cell level. However, without the Li compensation from the anode side, it faces much more challenging to achieve a long cycling life with a competitive energy density than Li metal-based batteries. Here, we prolong the lifespan of an anode-free Li metal battery by introducing Li-rich Li2 [Ni0.8 Co0.1 Mn0.1 ]O2 into the cathode as a Li-ions extender. The Li2 [Ni0.8 Co0.1 Mn0.1 ]O2 can release a large amount of Li-ions during the first charging process to supplement the Li loss in the anode, then convert into NCM811, thus extending the lifespan of the battery without the introduction of inactive elements. By the benefit of Li-rich cathode and high reversibility of Li metal on Cu foil, the anode-free pouch cells enable to achieve 447 Wh kg-1 energy density and 84 % capacity retention after 100 cycles in the condition of limited electrolyte addition (E/C ratio of 2 g Ah-1 ).

Summary Oxygen activity in highly delithiated LiCoO2 is critical to fully utilizing the energy density of this high-tap-density cathode but still lacks a clear understanding. In this work, we combined the results of several experimental techniques, especially resonant inelastic X-ray scattering (RIXS) and neutron pair distribution function (NPDF) analysis, together with theoretical calculations to study this topic. Our results conclude that oxygen redox takes place globally in the lattice, rather than forming localized dimerization as previously thought. RIXS results directly reveal the reversible oxygen redox, and NPDF results show that the O–O pair distance is considerably shortened in the highly delithiated LiCoO2. Theoretical calculations indicate that no O–O bonding is formed in LiCoO2, in sharp contrast to the lithium-rich system in which O–O bonding does form. These results provide the rationale for achieving a reversible deep delithiation and high energy density for LiCoO2-based electrodes.

The commercialization of rechargeable Li metal batteries is hindered by dendrite growth and volumetric variation. Herein, we report a Li-rich dual-phase Li-Cu alloy with built-in 3D conductive skeleton to replace conventional planar Li anode. The Li-Cu alloy is simply prepared by fusion of Li and Cu metals at a relatively low-temperature of 500 °C, followed by a cooling process where phase-segregation leads to metallic Li phase distributed in the network of LiCux solid solution phase. Different from the common Li alloy, the electrochemical alloying reaction between Li and Cu metals is not observed. Therefore, the lithiophilic LiCux nanowires guides conformal plating of Li and the porous framework provides superior dimensional stability for the anode. This unique ferroconcrete-like structure of Li-Cu alloy enables dendrite-free Li plating for an expanded cycling lifetime. Constructing a new type of Li alloy with in situ formed electrochemically inactive framework is a promising and easily scaled-up strategy toward practical application of Li metal anodes.

All-solid-state batteries have been considered as the ultimate solution for energy storage systems with high energy density and high safety. However, the obvious solid-solid contact and the interface stability issues pose great challenges to the construction of all-solid-state batteries with practically usable performances. Here, we discover that the heat-initiated polymerization of vinylene carbonate (VC) and the simultaneous incorporation of cathode electrolyte interphase (CEI) forming additive lithium difluoro(oxalato)borate (LiDFOB) can synergistically promote the formation of a high-voltage stable and low resistant interface layer between the cathode and solid electrolyte. A poly(ethylene oxide) PEO-based all-solid-state lithium battery (ASSLB) employing the LiCoO2 cathode electrode modified through such an in-situ CEI strategy demonstrates superior 4.2 ​V cycle stability, with a discharge capacity retention of 71.5% after 500 cycles. Besides, the accelerating rate calorimetry (ARC) test reveals that the cell displays extraordinary safety performance with no distinct thermal runaway below 350 ​°C. This work demonstrates an effective interface engineering strategy that can promise the formation of electrochemically and thermally stable cathode/solid electrolyte interface which is essential for the stable and safe operation of ASSLBs. Moreover, the validation of stable cycling of PEO-based ASSLBs at high voltages may encourage the efforts on further optimizations of interface engineering processes as well as large-scale fabrication, as the improvement of the energy-densities of PEO-based ASSLBs will be of paramount significance for practical applications.

In this study, we aimed to report a case of superior mesenteric artery syndrome, with a particular focus on the patient's non-surgical management including enteral nutrition therapy. The focus of this patient's care includes nasogastric tube management, parenteral and enteral nutrition care (personalized nutrition treatment plan), proper lying position, negative pressure drainage in the stomach, and psychiatric mental health nursing. This case study supports that with efforts focusing on patients’ nursing and enteral nutrition therapy, non-surgical management could be an effective approach in treating superior mesenteric artery compression syndrome.

Sn anode materials with high specific capacity are an appealing alternative to graphite for next-generation advanced lithium-ion batteries. However, poor electrochemical performance originating from fracture and pulverization due to the enormous volume changes during lithium alloying/dealloying hinders their commercial applications. Here, we propose the synthesis of a novel 3D structured Sn anode material by a facile method: heat treatment of nanosized SnO2 spheres in a tube furnace with a flowing mixed atmosphere of C2H2/Ar at 400 °C. After the heat treatment, the nanosized SnO2 spheres convert into pure Sn bulk material (~20 μm), which consists of Sn nanowires (~50 nm in diameter and several microns in length). This unique 3D structure with sufficient voids between the nanowires effectively mitigates the volume expansion of Sn bulk material and ensures good electrical contact between the anode material and conducting additives. As a consequence, the 3D structured Sn anode material exhibits a specific reversible capacity of ~600 mA h/g and no significant capacity degradation (compared with that of the 20th cycle) over 500 cycles at 0.2 C.

Structural design plays an essential role in the energy density of wearable batteries. Although various flexible materials have been developed to substitute traditional rigid components, current we...

The carbon-conducting additive-induced degradation of the cycling performance of lithium-ion batteries needs to be carefully controlled, particularly at a high operating voltage and elevated temperature. Herein, we report the investigation of surface coating with 2–3 nm of Al2O3, TiO2 and Ta2O5 oxides on Super P carbon black via atomic layer deposition. Detailed step potential tests revealed that after storage in EC/DMC electrolyte for 14 days at 55 °C, the stability of Ta2O5-coated Super P was the highest compared with those of Al2O3- and TiO2-coated counterparts. This result is attributed to Ta2O5 acting as a HF barrier, which mitigates the oxidation of electrolyte on the surface of Super P, as observed by XPS, thus showing less deposition of carbonate species. Further experiments showed that the surface of the Ta2O5 coating layer was stable, while the Al2O3 and TiO2 coating layers were completely dissolved in dilute HF after storage for 12 h Ta2O5-coated Super P was verified in a LiNi0.5Mn1.5O4 half-cell charged to 4.9 V at 55 °C. The results showed that with Ta2O5-coated Super P as the conducting additive, the half-cell exhibited an improved coulombic efficiency of 99.5%, compared with 98.3% for the pristine Super P.

The soft carbon precursor pitch, featured with low-cost and easy-availability, is regarded as a very promising candidate for the synthesis of carbonaceous anode. However, the Na-storage performance of pitch-derived carbon is strongly hindered by its highly graphitized structure, which mainly comes from the reordering during the fusion-state carbonization. To prevent the graphitization, herein, we propose an in-situ Mg(NO3)2·6H2O solidification strategy to convert the fusion-state to solid-state carbonization. The oxygen species and solid products generated from the decomposition of Mg(NO3)2·6H2O can retard the melting and reordering of pitch, thus tailoring the microstructure. The optimal sample displays outstanding overall performances in both half- and full-cells, with ~3-fold increase in capacity. Particularly, the carbon yield is significantly increased from 61% to 92% because less organic molecules can escape. The understandings gained in this work not only offer insights to adjust the carbonization process, but also provide solutions to obtain highly disordered carbon anodes from soft carbon precursors.

Summary All-solid-state lithium-metal batteries are regarded as promising next-generation battery systems. While thermal runaway in conventional Li-ion batteries is known to cause safety hazards, the thermal issues posed by highly reactive metallic lithium (Li) with non-flammable ceramic solid electrolytes (SEs) have been less studied but are critical for the safety of all-solid-state Li-metal batteries. Here, we quantify the thermal stability of four prevalent oxide SEs with metallic Li using the accelerating rate calorimeter (ARC). Thermal runaway is observed during ARC tests for four widely used SEs when contacting with Li, while no obvious heat releases from garnet with Li. The oxygen generation from SEs at elevated temperatures is found to be responsible for the thermal runaway with Li. Our results indicate potential safety issues in all solid-state batteries (ASSBs) brought by highly reactive metallic Li and oxygen from SEs at increased temperatures, emphasizing the need for investigating thermal safety issues in ASSBs.

Successfully commercialized poly(ethylene oxide) (PEO)-based solid polymer batteries (SPBs) are expected to continuously play a key role in the next generation of high-energy density lithium-ion ba...

Lithium-ion batteries (LIBs) have become ubiquitous power sources for small electronic devices, electric vehicles, and stationary energy storage systems. Despite the success of LIBs which is acknowledged by their increasing commodity market, the historical evolution of the chemistry behind the LIB technologies is laden with obstacles and yet to be unambiguously documented. This Viewpoint outlines chronologically the most essential findings related to today's LIBs, including commercial electrode and electrolyte materials, but furthermore also depicts how the today popular and widely emerging solid-state batteries were instrumental at very early stages in the development of LIBs.