This Perspective discusses the prospective strategies for overcoming the stability and capacity trade-off associated with increased Ni content in layered Ni-rich LiNi x Co y Mn z O2 (NCM) and LiNi ...x Co y Al z O2 (NCA) cathodes. The Ni-rich NCM and NCA cathodes have largely replaced the LiCoO2 cathodes in commercial batteries because of their lower cost, higher energy density, good rate capability, and reliability that has been extensively field-tested. Nevertheless, they suffer from microcrack generation along grain boundaries and Ni3+/4+ reactivity that rapidly deteriorate electrochemical performance. Doping and coating have been efficient strategies in delaying the onset of the damage, but they fail to overcome the degradation. There are, however, alternative strategies that directly counter the inherent degradation through micro- and nanostructural modifications of the Ni-rich NCM and NCA cathodes.
The performance of the rechargeable Li metal battery anode is limited by the poor ionic conductivity and poor mechanical properties of its solid-electrolyte interphase (SEI) layer. To overcome this, ...a 3 : 1 v/v ethyl methyl carbonate (EMC) : fluoroethylene carbonate (FEC) containing 0.8 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 0.2 M lithium difluoro(oxalate)borate (LiDFOB) dual-salts with 0.05 M lithium hexafluorophosphate (LiPF
6
) was tested to promote the formation of a multitude of SEI-beneficial species. The resulting SEI layer was rich in LiF, Li
2
CO
3
, oligomeric and glass borates, Li
3
N, and Li
2
S, which enhanced its role as a protective yet Li
+
conductive film, stabilizing the lithium metal anode and minimizing dead lithium build-up. With a stable SEI, a Li/LiNi
0.59
Co
0.2
Mn
0.2
Al
0.01
O
2
Li-metal battery (LMB) retains 75% of its 177 mA h g
−1
specific discharge capacity for 500 hours at a coulombic efficiency of greater than 99.3% at the fast charge–discharge rate of 1.8 mA cm
−2
.
Nickel adds to the capacity of layered oxide cathodes of lithium-ion batteries but comprises their stability. We report a petal-grained LiNi0.89Co0.10Sb0.01O2 cathode that is, nevertheless, stable. ...The stability originates from the ordering of the nanosized grains in a dense, flower-petal-like array, where the elongated and nearly parallel grains radiate from the center to the surface. The ordering of the grains prevents microcrack generation from abrupt lattice changes of the stressful H2–H3 phase transition. The tight packing of the nanograins is conserved upon cycling, preventing destructive seepage of the electrolytic solution into the particles. The half-cell, cycling between 2.7–4.3 V versus Li/Li+ at a 0.5 C rate retains 95.0% of its initial capacity of 220 mAh g–1 after 100 cycles. The full-cell, cycling with a graphite anode and between 3.0–4.2 V at a 1 C rate, retains 83.9% of its initial capacity after 1000 cycles.
Sodium foil, promising for high‐energy‐density batteries, faces reversibility challenges due to its inherent reactivity and unstable solid electrolyte interphase (SEI) layer. In this study, a stable ...sodium metal battery (SMB) is achieved by tuning the electrolyte solvation structure through the addition of co‐solvent 2‐methyl tetrahydrofuran (MTHF) to diglyme (Dig). The introduction of cyclic ether‐based MTHF results in increased anion incorporation in the solvation structure, even at lower salt concentrations. Specifically, the anion stabilization capabilities of the environmentally sustainable MTHF co‐solvent lead to a contact‐ion pair‐based solvation structure. Time‐of‐flight mass spectroscopy analysis reveals that a shift toward an anion‐dominated solvation structure promotes the formation of a thin and uniform SEI layer. Consequently, employing a NaPF6‐based electrolyte with a Dig:MTHF ratio of 50% (v/v) binary solvent yields an average Coulombic efficiency of 99.72% for 300 cycles in Cu||Na cell cycling. Remarkably, at a C/2 cycling rate, Na||Na symmetric cell cycling demonstrates ultra‐long‐term stability exceeding 7000 h, and full cells with Na0.44MnO2 as a cathode retain 80% of their capacity after 500 cycles. This study systematically examines solvation structure, SEI layer composition, and electrochemical cycling, emphasizing the significance of MTHF‐based binary solvent mixtures for high‐performance SMBs.
In this study, introducing 2‐methyl tetrahydrofuran (MTHF) as a co‐solvent to diglyme (Dig) leads to a more anion‐dominated solvation structure even at low salt concentrations, thereby inducing a thin uniform solid electrolyte interphase (SEI) layer. The thin, robust SEI layer formed can promote long‐term stable electrochemical cycling of sodium metal anode, elucidating the critical role of anion stabilizing co‐solvents for stable sodium metal batteries.
Electrochemical water splitting is one of the most promising approaches for sustainable energy conversion and storage toward a future hydrogen society. This demands durable and affordable ...electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). In this study, we report the preparation of uniform Ni-P-O, Ni-S-O, and Ni-S-P-O electrocatalytic films on nickel foam (NF) substrates
via
flow cell-assisted electrodeposition. Remarkably, electrodeposition onto 12 cm
2
substrates was optimized by strategically varying critical parameters. The high quality and reproducibility of the materials is attributed to the use of a 3D-printed flow cell with a tailored design. Then, the as-fabricated electrodes were tested for overall water splitting in the same flow cell under alkaline conditions. The best-performing sample, NiSP/NF, required relatively low overpotentials of 93 mV for the HER and 259 mV for the OER to produce a current density of 10 mA cm
−2
. Importantly, the electrodeposited films underwent oxidation into amorphous nickel (oxy)hydroxides and oxidized S and P species, improving both HER and OER performance. The superior electrocatalytic performance of the Ni-S-P-O films originates from the unique reconstruction process during the HER/OER. Furthermore, the overall water splitting test using the NiSP/NF couple required a low cell voltage of only 1.85 V to deliver a current density of 100 mA cm
−2
. Overall, we demonstrate that high-quality electrocatalysts can be obtained using a simple and reproducible electrodeposition method in a robust 3D-printed flow cell.
A reproducible and efficient electrodeposition method in a 3D-printed flow cell is used to synthesize high-quality Ni-S-P-O films on nickel foam for overall water splitting.
We describe here the metal-templated transformation of carbon nitride (C3N4) into nitrogen-containing carbons as anodes for Li-ion batteries (LIBs). Changing the template from the carbon- and ...nitrogen-immiscible Cu powder to the carbon- and nitrogen-miscible Fe powder yields different carbons; while Fe templating produces graphitized carbons of low (<10%) nitrogen content and moderate pore volume, Cu templating yields high defect-density carbons of high (32–24%) nitrogen content and larger pore volume. The Li+ storage capacity of the high nitrogen content and larger pore volume Cu-templated carbons exceeds that of the more graphitic Fe-templated carbons due to added contribution from Li+ insertion/extraction from pores and defects and to reversible faradaic Li+ reaction with nitrogen atoms. The Cu-templated carbon annealed at 750 °C delivers the highest specific capacity of 900 mAh g–1 at 0.1 A g–1 and 275 mAh g–1 at 20 A g–1, while also achieving a 96% capacity retention after 2000 cycles at 2 A g–1. The fabrication of higher mass loading electrodes (4.5 mg cm–2) provided a maximum areal capacity of 2.6 mAh cm–2 at 0.45 mA cm–2 (0.1 A g–1), comparable to the capacities of commercial LIB cells and favorable compared to other reported carbon materials.
We present a framework for developing storylines of UK sea level rise to aid risk communication and coastal adaptation planning. Our approach builds on the UK national climate projections (UKCP18) ...and maintains the same physically consistent methods that preserve component correlations and traceability between global mean sea level (GMSL) and local relative sea level (RSL). Five example storylines are presented that represent singular trajectories of future sea level rise drawn from the underlying large Monte Carlo simulations. The first three storylines span the total range of the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6)
likely
range GMSL projections across the SSP1-2.6 and SSP5-8.5 scenarios. The final two storylines are based upon recent high-end storylines of GMSL presented in AR6 and the recent literature. Our results suggest that even the most optimistic sea level rise outcomes for the UK will require adaptation of up to 1 m of sea level rise for large sections of coastline by 2300. For the storyline most consistent with current international greenhouse gas emissions pledges and a moderate sea level rise response, UK capital cities will experience between about 1 and 2 m of sea level rise by 2300, with continued rise beyond 2300. The storyline based on the upper end of the AR6
likely
range sea level projections yields much larger values for UK capital cities that range between about 3 and 4 m at 2300. The two high-end scenarios, which are based on a recent study that showed accelerated sea level rise associated with ice sheet instability feedbacks, lead to sea level rise for UK capital cities at 2300 that range between about 8 m and 17 m. These magnitudes of rise would pose enormous challenges for UK coastal communities and are likely to be beyond the limits of adaptation at some locations.
Regular cannabis use is associated with cortex‐wide changes in spontaneous and oscillatory activity, although the functional significance of such changes remains unclear. We hypothesized that regular ...cannabis use would suppress spontaneous gamma activity in regions serving cognitive control and scale with task performance. Participants (34 cannabis users, 33 nonusers) underwent an interview regarding their substance use history and completed the Eriksen flanker task during magnetoencephalography (MEG). MEG data were imaged in the time‐frequency domain and virtual sensors were extracted from the peak voxels of the grand‐averaged oscillatory interference maps to quantify spontaneous gamma activity during the pre‐stimulus baseline period. We then assessed group‐level differences in spontaneous and oscillatory gamma activity, and their relationship with task performance and cannabis use metrics. Both groups exhibited a significant behavioral flanker interference effect, with slower responses during incongruent relative to congruent trials. Mixed‐model ANOVAs indicated significant gamma‐frequency neural interference effects in the left frontal eye fields (FEF) and left temporoparietal junction (TPJ). Further, a group‐by‐condition interaction was detected in the left FEF, with nonusers exhibiting stronger gamma oscillations during incongruent relative to congruent trials and cannabis users showing no difference. In addition, spontaneous gamma activity was sharply suppressed in cannabis users relative to nonusers in the left FEF and TPJ. Finally, spontaneous gamma activity in the left FEF and TPJ was associated with task performance across all participants, and greater cannabis use was associated with weaker spontaneous gamma activity in the left TPJ of the cannabis users. Regular cannabis use was associated with weaker spontaneous gamma in the TPJ and FEF. Further, the degree of use may be proportionally related to the degree of suppression in spontaneous activity in the left TPJ.
Regular cannabis use has sharply increased over the past decade due to widespread legalization, but the impact on the brain is poorly understood. Herein, we investigated whether such cannabis use alters neurophysiological activity using magnetoencephalography and found differences in spontaneous and oscillatory gamma activity in users that scaled with behavior.
The discovery of liquid battery electrolytes that facilitate the formation of stable solid electrolyte interphases (SEIs) to mitigate dendrite formation is imperative to enable lithium anodes in ...next‐generation energy‐dense batteries. Compared to traditional electrolyte solvents, tetrahydrofuran (THF)‐based electrolyte systems have demonstrated great success in enabling high‐stability lithium anodes by encouraging the decomposition of anions (instead of organic solvent) and thus generating inorganic‐rich SEIs. Herein, by employing a variety of different lithium salts (i.e., LiPF6, LiTFSI, LiFSI, and LiDFOB), it is demonstrated that electrolyte anions modulate the inorganic composition and resulting properties of the SEI. Through novel analytical time‐of‐flight secondary‐ion mass spectrometry methods, such as hierarchical clustering of depth profiles and compositional analysis using integrated yields, the chemical composition and morphology of the SEIs generated from each electrolyte system are examined. Notably, the LiDFOB electrolyte provides an exceptionally stable system to enable lithium anodes, delivering >1500 cycles at a current density of 0.5 mAh g−1 and a capacity of 0.5 mAh g−1 in symmetrical cells. Furthermore, Li//LFP cells using this electrolyte demonstrate high‐rate, reversible lithium storage, supplying 139 mAh g(LFP)−1 at C/2 (≈0.991 mAh cm−2, @ 0.61 mA cm−2) with 87.5% capacity retention over 300 cycles (average Coulombic efficiency >99.86%).
Tetrahydrofuran‐based electrolyte systems have demonstrated success in enabling high‐stability lithium anodes by encouraging the decomposition of anions (instead of organic solvent) and thus generating inorganic‐rich solid electrolyte interphases (SEIs). By employing a variety of different lithium salts (i.e., LiPF6, LiTFSI, LiFSI, and LiDFOB), it is demonstrated that electrolyte anions can improve the inorganic composition and resulting properties of the SEI.
Aqueous zinc-ion batteries are regarded as promising candidates for future energy storage devices because of their high safety. Due to the dissolution in the aqueous electrolytes, most vanadate-based ...zinc-ion batteries suffer from continuous capacity fading. In some cases, a capacity reactivation process can be observed in vanadate-based cathodes after capacity decay. Herein, we employed electrochemical methods and characterization techniques to study the reaction mechanism of capacity reactivation in Ag
0.33
V
2
O
5
cathodes. Our preliminary results suggested that the reactivation is due to an
in situ
crystalline structure evolution in the cathode materials. Under the electrochemical condition, a new phase Zn
3
(OH)
2
V
2
O
7
·2H
2
O irreversibly formed on the initial cathodes, which prevented the dissolution of vanadate and further resulted in the capacity increase. Moreover, we confirmed the unique intercalation pseudocapacitive behavior in the reconstructed Zn
3
(OH)
2
V
2
O
7
·2H
2
O, which provided fast ionic diffusion to facilitate electrochemical performance. Accordingly, our study offers a new understanding of the capacity change of the vanadate-based cathode materials and provides a more general explanation of the capacity reactivation in aqueous zinc-ion batteries.
Capacity reactivation involves the reconstruction of the cathode. Zn
3
(OH)
2
V
2
O
7
·2H
2
O, showing intercalation pseudocapacitive behavior, forms
in situ
on the Ag
0.33
V
2
O
5
cathode to prevent cathodic dissolution and activate the capacity.
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