Stress Relief Principle of Micron‐Sized Anodes with Large Volume Variation for Practical High‐Energy Lithium‐Ion Batteries

Abstract

Practical applications of high gravimetric and volumetric capacity anodes for next-generation lithium-ion batteries have attracted unprecedented attentions, but still faced challenges by their severe volume changes, rendering low Coulombic efficiency and fast capacity fading. Nano and void-engineering strategies had been extensively applied to overcome the large volume fluctuations causing the continuous irreversible reactions upon cycling, but they showed intrinsic limit in fabrication of practical electrode condition. Achieving high electrode density is particularly paramount factor in terms of the commercial feasibility, which is mainly dominated by the true density and tapping density of active material. Herein, based on finite element method calculation, micron-sized double passivation layered Si/C design is introduced with restrictive lithiation state, which can withstand the induced stress from Li insertion upon repeated cycling. Such design takes advantage in structural integrity during long-term cycling even at high gravimetric capacity (1400 mAh g −1). In 1 Ah pouch-type full-cell evaluation with high mass loading and electrode density (≈3.75 mAh cm −2 and ≈1.65 g cm −3), it demonstrates superior cycle stability without rapid capacity drop during 800 cycles.

Liquid Metal Remedies Silicon Microparticulates Toward Highly Stable and Superior Volumetric Lithium Storage

“…[6] During Li extraction, the particle shrinks with an ≈300% volume change and is finally pulverized, leading to mechanical failure, generation of irregular voids and excessive solid-electrolyte interphase (SEI) growth. [7,8] Some Si fragments lose electronic contact and become "dead" Si with trapped Li, which is fatal and results in rapid capacity deterioration. These issues are much more severe for microparticulates with large sizes and irregular shapes, making it very difficult to unlock the true potential of SiMPs as dense and thick electrodes in compact LIBs.…”

Engineering Molecular Polymerization for Template‐Free SiOx/C Hollow Spheres as Ultrastable Anodes in Lithium‐Ion Batteries

“…The discrepant electrochemical properties of the three SiO x /C anodes are possibly due to the following reasons: (1) The SiO x /C HS‐TA with the largest carbon content, which is conducive to the formation of a carbon network, features the lowest stress variation; [ 36 ] (2) The SiO x nanoclusters in the SiO x /C HS‐TA possess the smallest size, leading to the lowest volumetric change during the alloying‐dealloying process. [ 37 ] The SEM images recorded before and after cycling confirm that the SiO x /C HS‐TA anode shows more stable structure to withstand the deep lithiation and delithiation in comparison to the SiO x /C HS‐GA and SiO x /C HS‐GL anodes (Figure S21, Supporting Information). Therefore, the SiO x /C HS‐TA anode takes up an outstanding position for Li + ion storage.…”

Interface engineering towardhigh‐efficiencyalloy anode for next‐generation energy storage device

“…Porous structure such as macroporous, microporous, and mesoporous materials have also been synthesized and employed as alloy anode to accommodate the volume expansion upon cycling 117–119 . Kang et al fabricated a hierarchical micro/mesoporous cauliflower‐like silicon/silicon oxide (CF‐Si/SiOx) hybrid anode by the magnesiothermic reduction method 120 .…”