11 Lithium-Ion Battery—3D Micro-/Nano-Structuring, Modification …
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11.1.3 Laser Materials Processing
Laser materials processing in manufacturing of LIB is a rather new technological approach, which enables rapid manufacturing, high reliability, and a significant reduction of lithium-ion battery manufacturing costs. Cost-efficient ns-laser
cutting of electrodes was one of the first laser technologies, which were successfully
transferred to industrial high energy battery production [21–25]. A rather new technical approach is the laser patterning of battery materials, namely current collectors
(aluminum or copper), separator materials, and thin and thick film electrodes [e.g.,
LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC), LiFePO 4 (LFP), LiCoO 2 (LCO), LiMn 2 O 4 (LMO),
silicon (Si)] [12, 18, 26–28]. For each type of battery materials, laser structuring can
improve the battery lifetime, cycle stability, and high rate capability. The structuring
of the current collector foils can improve the electrode film adhesion which is a critical aspect for high energy and thick film electrodes [29]. The 3D battery concept
introduced to microbatteries by Notten et al. [30] and summarized in a review article
by Ferrari et al. [11] was transferred by the researchers at KIT to a new battery
concept by direct structuring of thick and thin-film electrodes for batteries with high
energy and power densities. A defined thermal impact can be advantageous in electrode manufacturing, already confirmed by laser annealing of thin-film electrodes for
adjusting of battery active crystalline phases [31–33]. Nanosecond laser or ultrafast
laser for direct structuring or printing of electrode materials can be used to realize
three-dimensional (3D) electrode architectures. Furthermore, it was shown that introducing 3D micro-/nano-structures will improve the electrolyte wetting even of thick
film composite electrodes. Laser structuring can modify electrodes and separators
into superwicking materials, enhancing the battery lifetime and its performance [12].
A main issue in laser materials processing is the process up-scaling with respect to
large electrode footprint areas, e.g., for batteries with pouch cell design, and the laser
processing speed, which should be adapted to the standards in battery manufacturing
for high energy and high power lithium-ion cells.
11.2 Micro-/Nano-Structuring of Current Collectors
The electrode film has to withstand mechanical demands during cell assembling,
and thereafter, during repeated cell operation, when lithium-ion intercalation and
de-intercalation occur, due to expansion and shrinkage of the electrochemically
active material particles. Within state-of-the-art LIBs, graphite anodes with a practical capacity in the range of 330–372 mAh/g are applied. During charging and
discharging the graphite anode undergoes a volume expansion of about 10% [34].
For next generation LIBs, silicon (Si) or silicon-doped graphite (Si/C) have been
regarded as the most promising anode material due to a high theoretical energy
density of Si of about 4200 mAh/g [35]. High energy batteries using a significant
315
11.1.3 Laser Materials Processing
Laser materials processing in manufacturing of LIB is a rather new technological approach, which enables rapid manufacturing, high reliability, and a significant reduction of lithium-ion battery manufacturing costs. Cost-efficient ns-laser
cutting of electrodes was one of the first laser technologies, which were successfully
transferred to industrial high energy battery production [21–25]. A rather new technical approach is the laser patterning of battery materials, namely current collectors
(aluminum or copper), separator materials, and thin and thick film electrodes [e.g.,
LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC), LiFePO 4 (LFP), LiCoO 2 (LCO), LiMn 2 O 4 (LMO),
silicon (Si)] [12, 18, 26–28]. For each type of battery materials, laser structuring can
improve the battery lifetime, cycle stability, and high rate capability. The structuring
of the current collector foils can improve the electrode film adhesion which is a critical aspect for high energy and thick film electrodes [29]. The 3D battery concept
introduced to microbatteries by Notten et al. [30] and summarized in a review article
by Ferrari et al. [11] was transferred by the researchers at KIT to a new battery
concept by direct structuring of thick and thin-film electrodes for batteries with high
energy and power densities. A defined thermal impact can be advantageous in electrode manufacturing, already confirmed by laser annealing of thin-film electrodes for
adjusting of battery active crystalline phases [31–33]. Nanosecond laser or ultrafast
laser for direct structuring or printing of electrode materials can be used to realize
three-dimensional (3D) electrode architectures. Furthermore, it was shown that introducing 3D micro-/nano-structures will improve the electrolyte wetting even of thick
film composite electrodes. Laser structuring can modify electrodes and separators
into superwicking materials, enhancing the battery lifetime and its performance [12].
A main issue in laser materials processing is the process up-scaling with respect to
large electrode footprint areas, e.g., for batteries with pouch cell design, and the laser
processing speed, which should be adapted to the standards in battery manufacturing
for high energy and high power lithium-ion cells.
11.2 Micro-/Nano-Structuring of Current Collectors
The electrode film has to withstand mechanical demands during cell assembling,
and thereafter, during repeated cell operation, when lithium-ion intercalation and
de-intercalation occur, due to expansion and shrinkage of the electrochemically
active material particles. Within state-of-the-art LIBs, graphite anodes with a practical capacity in the range of 330–372 mAh/g are applied. During charging and
discharging the graphite anode undergoes a volume expansion of about 10% [34].
For next generation LIBs, silicon (Si) or silicon-doped graphite (Si/C) have been
regarded as the most promising anode material due to a high theoretical energy
density of Si of about 4200 mAh/g [35]. High energy batteries using a significant