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Page 2 of 11 Lv et al. Energy Mater 2024;4:400018 https://dx.doi.org/10.20517/energymater.2023.90

INTRODUCTION
With increasing demand for high energy density and excellent stability electrodes in next-generation
lithium (Li) batteries, metal-based electrodes have attracted widespread attention due to their high specific
capacity and outstanding electrode reaction catalytic function . Alloy-type anode materials possessing
[1-3]
numerous advantages with a high theoretical specific capacity, large volume energy density, low cost and
moderate working potential to lithium could achieve efficient energy storage during Li alloying/dealloying,
[4-6]
which makes them the most promising anode materials for next-generation rechargeable batteries .
Unfortunately, several problems remain, restricting their applications: (1) the inevitable volume expansion
of the alloy-type anode during the lithiation process causes huge stress and strain on the material, which
further causes cracking and pulverization, poor contact between the electrode materials and the current
collectors; and (2) volume swelling during charge/discharge break the solid electrolyte Interphase (SEI) film
on the surface of anodes, during subsequent charge/discharge cycle, the electrolyte will react with the newly
exposed materials to form new SEI films, resulting in continuous consumption of electrolyte and increasing
thickness of the SEI film, which will aggravate the decay of battery capacity. In efforts to address these
challenges, a multitude of strategies have been proposed in the past years, involving the use of a wide variety
of porous metal or liquid metal (LM)-based materials [7-11] , gradient multi-porous metal electrodes [12,13] ,
electrolyte additives [14,15] , artificial SEI films [16,17] , etc., which have been emerged in endlessly. Especially room
temperature LM-based materials [18-20] not only have the self-healing property but also alleviate the
generation of Li dendrite and volume expansion during the cycle process, and they also possess a high Li
storage capacity and suitable Li-alloying potential. However, the inherent disadvantages, such as fluidity and
high surface tensions, restrict their spreading over most of the current collectors, resulting in a significant
decline in battery life span and capacity fading; these problems have attracted extensive attention in recent
[21]
years .

LM anodes at room temperature mainly include metallic Hg and Ga, alloys NaK, GaSn, GaIn and GaInSn,
etc. Among them, GaInSn ternary alloys (mass ratio is 7:2:1, referred to as LM later), owing to numerous
special properties including the lowest melting point (10 °C), high surface tension (718 mN/m), high
electronic conductivity (3.5 × 10 S/m), low viscosity (2.4 mPa s), low toxicity, self-healing ability, and
6
chemical stability, have been widely applied in flexible electronics, energy storage, biomedicine health,
etc. [22-24] . Moreover, another important aspect of choosing the ternary alloy is having an “active-active-active”
composite where all the elements are active with Li or alloys with Li, which enables better physical and
[25]
electrochemical properties . However, there is poor interfacial contact between pure LM and current
collectors, and it is difficult to form a composite electrode. At present, abundant effective strategies have
been put forward to improve the wettability of LM on current collectors, such as modifying current
collectors [26,27] and interface decoration [28,29] . Nevertheless, related research has rarely yet been reported on
changing the feature of LM itself. Thus, it is necessary to develop a new strategy to modify the fluidity and
high surface tension properties of LM itself, and the inherent mechanism should be further clarified. In
addition, the preparation of anodes usually will mix conductive carbon material and electron-insulating
binders, which may cause the Li ion battery in the high-rate charge/discharge to encounter side reactions
and larger intrinsic resistance or intangible costs, resulting in the deterioration of battery performance.

Inspired by the fact that high-melting-point metal particles mixed with LM could form an unalloyed
cohesive mixture , we report a facial LM-W10 anode fabrication strategy by introducing tungsten (W)
[29]
nanoparticles (φ 50 nm, 10 wt.%) to reducing the fluidity and surface tension of LM. After being mixed, the
binder- and conductor-free LM-W10 anode presents low surface tension and high viscosity characteristics,
and the composite can be easily dispersed over the current collector. A close contact interface can be thus
obtained, and the reversible Li storage performance has been achieved. The present work indicates great
application prospects in room temperature 3D printing manufacture of flexible devices.