Sa Li

Aqueous Zn–LiMn ₂ O ₄ hybrid‐ion batteries are promising for large‐scale energy storage due to their high energy density, environmental friendliness, and low cost. However, conventional aqueous electrolytes suffer from two critical challenges: zinc anode side reactions and manganese dissolution from the LiMn ₂ O ₄ cathode. To address these issues, a novel hybrid electrolyte regulated by a methylsulfonylmethane (MSM) additive is introduced. This electrolyte effectively suppresses zinc dendrite growth by promoting uniform Zn ²⁺ deposition. Additionally, the modified Zn ²⁺ solvation structure, with reduced water coordination, mitigates hydrogen evolution, interfacial corrosion, and by‐product formation. As a result, Zn||Zn symmetric cells exhibit stable zinc plating/stripping for over 1600 h. Furthermore, MSM disrupts the tight hydrogen bonding network of the hybrid electrolyte, lowering viscosity and enhancing ion mobility, which reduces voltage polarization and improves the rate capability of Zn–LiMn ₂ O ₄ cells. Moreover, the hybrid electrolyte stabilizes the cathode structure by inhibiting manganese disproportionation at high voltages, attributed to an increased oxygen evolution reaction overpotential and the formation of an in situ cathode‐electrolyte interphase. Consequently, Zn–LiMn₂O₄ full cells achieve exceptional cycling stability, retaining 71.1% of their capacity after 800 cycles at 0.15 A g ⁻¹ .

Contact prelithiation for anodes is a promising strategy to compensate for active lithium loss due to solid-state interface formation. However, existing research has predominantly focused on lithium thinning, neglecting issues of low lithium utilization and side reactions associated with lithium purification. Residues on the electrode surface can provoke additional side reactions, exacerbating cycling instability. Moreover, the thermal effects during contact prelithiation raise significant safety concerns for practical applications and remain understudied. To address surface issues, the lithium inventory was repositioned beneath the electrode using a lithiable current collector, sandwiching LiAg foil between two Cu foils (CLC). A 16 μm-thick CLC embedded with 5 μm LiAg was fabricated through a rolling process, while Cu foils underwent deformation, creating microholes during the thinning process. These microholes facilitate the sustained release of Li⁺ from CLC, thus mitigating Li plating without additional anode materials. The gradual release of Li⁺ also suppresses thermal runaway and electrode deformation, especially for Si anodes. Moreover, the CLC demonstrates excellent air stability, making it suitable as a current collector. The continuous electron pathway in CLC ensures a high lithium utilization of 97%. When integrated into LFP||Gr full cells, CLC enhances capacity retention from 80% to 96% after 400 cycles.

A green and energy-efficient strategy to recrystallize industrial spent LiFePO₄ into a functional material that is comparable with commercial new LiFePO₄.

The practical application of lithium metal batteries is hindered by the poor reversibility and large volume change caused by the uncontrollable dendritic growth and the highly reactive surface. In this work, favorable Li deposition is achieved by generating gradient lithiophilicity and conductivity in an Ag-decorated graphene/holey graphene film (G-HGA). Dendrite-free Li metal is deposited on the G-HGA matrix, which greatly reduces the surface area and suppresses the side reaction between the electrolyte and the dendritic Li. The average Li-metal plating–stripping coulombic efficiency (CE) on the G-HGA matrix maintains ∼98.7% over 350 cycles, compared to a worse average CE (∼97.3%) with the bare Cu matrix, only for less than 100 cycles. A full cell constructed by using LiFePO₄ and prelithiated G-HGA exhibits excellent rate capability and a high capacity retention of 99.6% for 175 cycles at a low negative to positive capacity ratio of 1.13. This advanced design can inspire further development of high-energy and long-lived Li-metal batteries.

Metal foils are used for packaging and decoration, and gold leaf down to 0.1 μm thickness has been made since ancient Egyptian times. The chemical inertness of gold, causing non-stickiness, and its malleability, underlie the success of “Goldbeating”. In contrast, lithium metal is extremely reactive and sticks to rollers as well as degrades in air. How to make one-to-few μm thick, large-area lithium foil is a key challenge for the battery industry, as such foils can provide extraordinarily longer cycle life to rechargeable batteries when standard anodes such as graphite or silicon are prelithiated right before cell assembly, by mechanically pressing the thin foil to the anode. Here, we show that the addition of a small alloy-element on the order of 1 at% to the body-centered cubic (BCC) phase drastically changes the oxidized surface layer composition, making the Li alloy much less sticky towards the rolling machine. By forming a protective passivation layer, the air stability is dramatically enhanced, so it can be stored for up to 12 hours without significant performance degradation. Also, there is a 10× strengthening effect, making the sheet much less prone to ductile rupture damage during rolling, while maintaining malleability. As a result, we are able to fabricate large-area lithium foil in a roll-to-roll manner down to 1 μm thickness. Such an ultra-thin Li foil anode demonstrates superior electrochemical performance directly in pouch cells (>320 W h kg⁻¹), in which the 0.8 A h pouch-cell achieved a 100 cycle life under lean electrolyte conditions of 2.67 g A h⁻¹. Furthermore, we applied 5 μm Li to graphite prelithiation, having an extra 1 mA h cm⁻² lithium inventory (the amount of cyclable lithium in a full cell), the capacity of the LFP//graphite full cell increases by 18%, with an average coulombic efficiency of >99.99% over more than 300 cycles.

Due to the poor electronic conductivity of solid sulfur and sulfides, the dissolution of S^α- (α = 0, 2/8, 2/6, 2/4) into a liquid electrolyte and the vehicular diffusion of S^α- to carbon black are necessary for the electrochemical activity of a sulfur cathode in lithium-sulfur (Li-S) batteries. However, exactly how much dissolution and diffusion are required for high sulfur utilization and how this may control the minimum electrolyte/sulfur ratio, (E/S)_min, have not been quantitatively settled. In this work, we show experimentally that a dissolved polysulfide concentration which is too high (>10-20 MS) may gel the liquid electrolyte, leading to catastrophic loss of S^α- mobility, a failure mode that is especially susceptible in a high-donor-number (DN) electrolyte under a lean condition (low E/S), similar to a traffic jam, resulting in high electrochemical polarization and low sulfur utilization. In contrast, we show that a low-DN electrolyte, even with a low polysulfide solubility of 0.1-0.5 MS, will never encounter a gelation catastrophe even at extremely low E/S, leading to unprecedentedly high energy density. Specifically, high sulfur utilizations of 96% (1600 mAh g^-1) and 78% (1300 mAh g^-1) are reached in an electrolyte as lean as E/S = 2 and 1 μL mg^-1 Li-S coin cells when DME_1.6LiFSI-HFE of low solvation capability (DN = 13.9) is adopted, even paired against a high-sulfur-loading cathode (5 mg cm^-2).

Lithium metal has been considered as an ultimate anode choice for next‐generation secondary batteries due to its low density, superhigh theoretical specific capacity and the lowest voltage potential. Nevertheless, uncontrollable dendrite growth and consequently large volume change during stripping/plating cycles can cause unsatisfied operation efficiency and serious safety concern, restraining its commercial use for the last 40 years. As widely used lithium‐ion battery is approaching its theoretical limit at present, it is increasingly urgent to develop new energy storage equipment with sufficient practical capacity. Herein, two important processes of lithium deposition, nucleation and growth on lithium metal anode are reviewed. Modified three‐dimensional (3D) porous anodes with unique structure and dynamic surface conditions, as one of the most efficient designs on dendrites suppression, are specifically discussed in terms of their beneficial adjustment on the dendrite formation. Problems on current designs and prospects on future advanced porous anode are explored in the end.

Anode prelithiation could dramatically improve the initial Coulombic efficiency and battery life. Roll-to-roll mechanical prelithiation (MP) is an attractive option for achieving prelithiation in minutes. While our previous work on metallic-foil prelithiation revealed that an external pressure is necessary to achieve MP in a timely fashion, too high an applied pressure will cause severe damages in the form of porosity and cracking. Thus, gentler MP under smaller pressure, and surprisingly, cryogenic temperatures, while prepositioning prolific grain boundaries as lithium diffusion paths is critical. To this end, first, we developed an accumulative roll bonding (ARB) method to refine the grain size of Sn–5Sb foil for denser grain boundaries. After ARB of 12 cycles (ARB-12), the grain size of Sn–5Sb foil decreased from 20–50 to 0.5–1.5 μm. Then, MP was performed under a mild condition of 0.5 MPa and −20 °C. Thereby, the porosity of prelithiated ARB-12 was reduced to 1.8% from thickness measurement, significantly minimizing the prelithiation damage. As a result, due to grain refinement, we achieved lower interface impedance and better rate performance. The ARB-12 Sn–5Sb foil with a proper prelithiation design exhibited 180 and 110 stable cycles when pairing with commercial LFP and NCM811 cathodes. Furthermore, it also depletes less electrolyte and keeps higher capacity retention under −10 °C than that of the graphite anode.