Page 54 - Read Online

Page 2 of 21 Guo et al. Energy Mater. 2025, 5, 500041 https://dx.doi.org/10.20517/energymater.2024.214

INTRODUCTION
The groundbreaking rechargeable lithium-ion battery (LIB), conceived by Goodenough et al. and
[1,2]
Scrosati et al., has evolved into a mature technology . Today, these enhanced LIBs have achieved
widespread adoption across diverse sectors, including portable electronics, electric vehicles, and pivotal
[3,4]
energy storage systems . Prevalent LIBs employ organic liquid electrolytes due to their outstanding ionic
conductivity and exceptional electrode compatibility. Nevertheless, their inherent vulnerabilities, such as
poor thermal stability and low ignition thresholds, pose a latent threat to human life and property . Solid-
[5,6]
state batteries (SSBs) exhibit significant advantages in terms of safety, energy density, and cycle life, making
them a key development direction for future battery technology . As the demands for battery endurance
[7,8]
and fast-charging performance continue to increase, research institutions and enterprises have come to
highly value lithium metal batteries. This is because lithium metal, when used as the anode, has a much
higher theoretical capacity than graphite anodes in traditional LIBs. Additionally, lithium metal batteries
can rapidly discharge a large amount of energy, making them ideal for applications requiring high power
output. Since the interfacial compatibility between solid polymer electrolytes (SPEs) and lithium metal
anodes is excellent, significantly minimizing interfacial side reactions [9-12] , SPEs emerge as an ideal candidate
for use with lithium metal anodes. Their ability to maintain stability with lithium metal and reduce dendrite
growth also makes them suitable for lithium metal batteries [13-15] .

Although SPEs show better interfacial contact than inorganic solid-state electrolytes, polymer-based
electrolytes continue to grapple with challenges pertaining to effective penetration and wettability within
cathodes, particularly when paired with high-mass-loading cathodes [16,17] . Polymer electrolytes in lithium
batteries suffer from suboptimal electrochemical performance due to issues such as interfacial side
+
reactions, limited Li interfacial transport, and the formation of a detrimental space-charge layer at the
electrode/electrolyte interface [18-20] . Addressing these interfacial issues can increase battery energy density
and extend its lifespan. This concise review summarizes advanced strategies aimed at modifying and
optimizing electrode/electrolyte surfaces. However, while post-disassembly characterization offers valuable
insights into interfacial morphology and microstructure, it lacks the capability to provide real-time feedback
on the complex dynamics occurring at electrodes, electrolytes, and their interfaces during battery operation.
Recently, Ning et al. have visualized crack propagation in Li PS Cl solid electrolyte (SE) using in situ X-ray
5
6
computed tomography (XRCT) and spatially resolved X-ray diffraction techniques . Zhao et al. have
[21]
devised a mesoscale electrochemical apparatus integrated within a focused ion beam-scanning electron
microscopy (FIB-SEM), enabling real-time visualization of Li deposition and cracking in Li La Zr Ta O
6.4
0.6
12
3
1.4
(LLZTO) SEs at nanoscale precision . However, these advanced in-situ characterization methods are
[22]
primarily employed for monitoring lithium batteries based on inorganic SEs [23,24] . As SPEs evolve, in-situ
characterization techniques have been used to monitor internal battery changes. This review summarizes
recent efforts in using these techniques to study lithium batteries with polymer electrolytes. These
techniques help researchers understand battery material behavior during charging/discharging, guiding the
design of higher-energy-density electrode materials and electrolytes.
The development of in-situ characterization techniques has significantly facilitated the resolution of crucial
scientific issues in the field of lithium batteries, but monitoring the complex physical and chemical
processes is expensive and time-consuming. Theoretical calculations and simulations can provide
information without consuming any physical resources, saving both manpower and material resources.
Some experiments are difficult or impossible to conduct under realistic conditions, such as those in
extremely high temperatures, high pressures, or toxic environments, while theoretical analysis and
simulation calculations are not constrained by these limitations. Advancements in theoretical concepts and
methodologies across related disciplines such as solid-state physics, quantum chemistry, statistical